ANNEX I

SCOPE, DEFINITIONS AND ABBREVIATIONS, APPLICATION FOR EC TYPE-APPROVAL, SPECIFICATIONS AND TESTS AND CONFORMITY OF PRODUCTION

1.   SCOPE

This Directive applies to the gaseous and particulate pollutants from all motor vehicles equipped with compression-ignition engines and to the gaseous pollutants from all motor vehicles equipped with positive ignition engines fuelled with natural gas or LPG, and to compression-ignition and positive ignition engines as specified in Article 1 with the exception of those vehicles of category N1, N2 and M2 for which type-approval has been granted under Council Directive 70/220/EEC of 20 March 1970 on the approximation of the laws of the Member States on measures to be taken against air pollution by emissions from motor vehicles (1).

2.   DEFINITIONS AND ABBREVIATIONS

For the purposes of this Directive:

2.1.   ‘test cycle’ means a sequence of test points each with a defined speed and torque to be followed by the engine under steady state (ESC test) or transient operating conditions (ETC, ELR test);

2.2.   ‘approval of an engine (engine family)’ means the approval of an engine type (engine family) with regard to the level of the emission of gaseous and particulate pollutants;

2.3.   ‘diesel engine’ means an engine which works on the compression-ignition principle;

2.4.   ‘gas engine’ means an engine which is fuelled with natural gas (NG) or liquid petroleum gas (LPG);

2.5.   ‘engine type’ means a category of engines which do not differ in such essential respects as engine characteristics as defined in Annex II to this Directive;

2.6.   ‘engine family’ means a manufacturers grouping of engines which, through their design as defined in Annex II, Appendix 2 to this Directive, have similar exhaust emission characteristics; all members of the family must comply with the applicable emission limit values;

2.7.   ‘parent engine’ means an engine selected from an engine family in such a way that its emissions characteristics will be representative for that engine family;

2.8.   ‘gaseous pollutants’ means carbon monoxide, hydrocarbons (assuming a ratio of CH1,85 for diesel, CH2,525 for LPG and CH2,93 for NG (NMHC), and an assumed molecule CH3O0,5 for ethanol-fuelled diesel engines), methane (assuming a ratio of CH4 for NG) and oxides of nitrogen, the last named being expressed in nitrogen dioxide (NO2) equivalent;

2.9.   ‘particulate pollutants’ means any material collected on a specified filter medium after diluting the exhaust with clean filtered air so that the temperature does not exceed 325 K (52 oC);

2.10.   ‘smoke’ means particles suspended in the exhaust stream of a diesel engine which absorb, reflect, or refract light;

2.11.   ‘net power’ means the power in EC kW obtained on the test bench at the end of the crankshaft, or its equivalent, measured in accordance with the EC method of measuring power as set out in Council Directive 80/1269/EEC of 16 December 1980on the approximation of the laws of the Member States relating to the engine power of motor vehicles (2);

2.12.   ‘declared maximum power (Pmax)’ means the maximum power in EC kW (net power) as declared by the manufacturer in his application for type-approval;

2.13.   ‘per cent load’ means the fraction of the maximum available torque at an engine speed;

2.14.   ‘ESC test’ means a test cycle consisting of 13 steady state modes to be applied in accordance with Section 6.2 of this Annex;

2.15.   ‘ELR test’ means a test cycle consisting of a sequence of load steps at constant engine speeds to be applied in accordance with Section 6.2 of this Annex;

2.16.   ‘ETC test’ means a test cycle consisting of 1 800 second-by-second transient modes to be applied in accordance with Section 6.2 of this Annex;

2.17.   ‘engine operating speed range’ means the engine speed range, most frequently used during engine field operation, which lies between the low and high speeds, as set out in Annex III to this Directive;

2.18.   ‘low speed (nlo)’ means the lowest engine speed where 50 % of the declared maximum power occurs;

2.19.   ‘high speed (nhi)’ means the highest engine speed where 70 % of the declared maximum power occurs;

2.20.   ‘engine speeds A, B and C’ means the test speeds within the engine operating speed range to be used for the ESC test and the ELR test, as set out in Annex III, Appendix 1 to this Directive;

2.21.   ‘control area’ means the area between the engine speeds A and C and between 25 to 100 per cent load;

2.22.   ‘reference speed (nref)’ means the 100 per cent speed value to be used for denormalising the relative speed values of the ETC test, as set out in Annex III, Appendix 2 to this Directive;

2.23.   ‘opacimeter’ means an instrument designed to measure the opacity of smoke particles by means of the light extinction principle;

2.24.   ‘NG gas range’ means one of the H or L range as defined in European Standard EN 437, dated November 1993;

2.25.   ‘self adaptability’ means any engine device allowing the air/fuel ratio to be kept constant;

2.26.   ‘recalibration’ means a fine tuning of an NG engine in order to provide the same performance (power, fuel consumption) in a different range of natural gas;

2.27.   ‘Wobbe Index (lower Wl; or upper Wu)’ means the ratio of the corresponding calorific value of a gas per unit volume and the square root of its relative density under the same reference conditions:

2.28.   ‘λ-shift factor (Sλ)’ means an expression that describes the required flexibility of the engine management system regarding a change of the excess-air ratio λ if the engine is fuelled with a gas composition different from pure methane (see Annex VII for the calculation of Sλ);

2.29.   ‘defeat device’ means a device which measures, senses or responds to operating variables (e.g. vehicle speed, engine speed, gear used, temperature, intake pressure or any other parameter) for the purpose of activating, modulating, delaying or deactivating the operation of any component or function of the emission control system such that the effectiveness of the emission control system is reduced under conditions encountered during normal vehicle use unless the use of such a device is substantially included in the applied emission certification test procedures.

2.30.   ‘auxiliary control device’ means a system, function or control strategy installed to an engine or on a vehicle, that is used to protect the engine and/or its ancillary equipment against operating conditions that could result in damage or failure, or is used to facilitate engine starting. An auxiliary control device may also be a strategy or measure that has been satisfactorily demonstrated not to be a defeat device;

2.31.   ‘irrational emission control strategy’ means any strategy or measure that, when the vehicle is operated under normal conditions of use, reduces the effectiveness of the emission control system to a level below that expected on the applicable emission test procedures.

2.32.   Symbols and abbreviations

2.32.1.   Symbols for test parameters

2.32.2.   Symbols for chemical components

2.32.3.   Abbreviations

3.   APPLICATION FOR EC TYPE-APPROVAL

3.1.   Application for EC type-approval for a type of engine or engine family as a separate technical unit

3.1.1.   The application for approval of an engine type or engine family with regard to the level of the emission of gaseous and particulate pollutants for diesel engines and with regard to the level of the emission of gaseous pollutants for gas engines shall be submitted by the engine manufacturer or by a duly accredited representative.

3.1.2.   It shall be accompanied by the undermentioned documents in triplicate and the following particulars:

3.1.2.1.   A description of the engine type or engine family, if applicable, comprising the particulars referred to in Annex II to this Directive which conform to the requirements of Articles 3 and 4 of Directive 70/156/EEC of 6 February 1970 on the approximation of the laws of the Member States relating to the type-approval of motor vehicles and their trailers (3).

3.1.3.   An engine conforming to the ‘engine type’ or ‘parent engine’ characteristics described in Annex II shall be submitted to the technical service responsible for conducting the approval tests defined in Section 6.

3.2.   Application for EC type-approval for a vehicle type in respect of its engine

3.2.1.   The application for approval of a vehicle with regard to emission of gaseous and particulate pollutants by its diesel engine or engine family and with regard to the level of the emission of gaseous pollutants by its gas engine or engine family shall be submitted by the vehicle manufacturer or a duly accredited representative.

3.2.2.   It shall be accompanied by the undermentioned documents in triplicate and the following particulars:

3.2.2.1.   A description of the vehicle type, of the engine-related vehicle parts and of the engine type or engine family, if applicable, comprising the particulars referred to in Annex II, along with the documentation required in application of Article 3 of Directive 70/156/EEC.

3.3.   Application for EC type-approval for a vehicle type with an approved engine

3.3.1.   The application for approval of a vehicle with regard to emission of gaseous and particulate pollutants by its approved diesel engine or engine family and with regard to the level of the emission of gaseous pollutants by its approved gas engine or engine family shall be submitted by the vehicle manufacturer or a duly accredited representative.

3.3.2.   It shall be accompanied by the undermentioned documents in triplicate and the following particulars:

3.3.2.1.   a description of the vehicle type and of engine-related vehicle parts comprising the particulars referred to in Annex II, as applicable, and a copy of the EC Type-Approval Certificate (Annex VI) for the engine or engine family, if applicable, as a separate technical unit which is installed in the vehicle type, along with the documentation required in application of Article 3 of Directive 70/156/EEC.

4.   EC TYPE-APPROVAL

4.1.   Granting of a universal fuel EC type-approval

A universal fuel EC type-approval is granted subject to the following requirements.

4.1.1.   In the case of diesel fuel the parent engine meets the requirements of this Directive on the reference fuel specified in Annex IV.

4.1.2.   In the case of natural gas the parent engine should demonstrate its capability to adapt to any fuel composition that may occur across the market. In the case of natural gas there are generally two types of fuel, high calorific fuel (H-gas) and low calorific fuel (L-gas), but with a significant spread within both ranges; they differ significantly in their energy content expressed by the Wobbe Index and in their λ-shift factor (Sλ). The formulae for the calculation of the Wobbe index and Sλ are given in Sections 2.27 and 2.28. Natural gases with a λ-shift factor between 0,89 and 1,08 (0,89 ≤ Sλ ≤ 1,08) are considered to belong to H-range, while natural gases with a λ-shift factor between 1,08 and 1,19 (1,08 ≤ Sλ ≤ 1,19) are considered to belong to L-range. The composition of the reference fuels reflects the extreme variations of Sλ.

The parent engine shall meet the requirements of this Directive on the reference fuels GR (fuel 1) and G25 (fuel 2), as specified in Annex IV, without any readjustment to the fuelling between the two tests. However, one adaptation run over one ETC cycle without measurement is permitted after the change of the fuel. Before testing, the parent engine shall be run-in using the procedure given in paragraph 3 of Appendix 2 to Annex III.

4.1.2.1.   On the manufacturer's request the engine may be tested on a third fuel (fuel 3) if the λ-shift factor (Sλ) lies between 0,89 (i.e. the lower range of GR) and 1,19 (i.e. the upper range of G25) for example when fuel 3 is a market fuel. The results of this test may be used as a basis for the evaluation of the conformity of the production.

4.1.3.   In the case of an engine fuelled with natural gas which is self-adaptive for the range of H-gases on the one hand and the range of L-gases on the other hand, and which switches between the H-range and the L-range by means of a switch, the parent engine shall be tested on the relevant reference fuel as specified in Annex IV for each range, at each position of the switch. The fuels are GR (fuel 1) and G23 (fuel 3) for the H-range of gases and G25 (fuel 2) and G23 (fuel 3) for the L-range of gases. The parent engine shall meet the requirements of this Directive at both positions of the switch without any readjustment to the fuelling between the two tests at each position of the switch. However, one adaptation run over one ETC cycle without measurement is permitted after the change of the fuel. Before testing the parent engine shall be run-in using the procedure given in paragraph 3 of Appendix 2 to Annex III.

4.1.3.1.   At the manufacturer's request the engine may be tested on a third fuel instead of G23 (fuel 3) if the λ-shift factor (Sλ) lies between 0,89 (i.e. the lower range of GR) and 1,19 (i.e. the upper range of G25), for example when fuel 3 is a market fuel. The results of this test may be used as a basis for the evaluation of the conformity of the production.

4.1.4.   In the case of natural gas engines, the ratio of the emission results ‘r’ shall be determined for each pollutant as follows:

or,

and,

4.1.5.   In the case of LPG the parent engine should demonstrate its capability to adapt to any fuel composition that may occur across the market. In the case of LPG there are variations in C3/C4 composition. These variations are reflected in the reference fuels. The parent engine should meet the emission requirements on the reference fuels A and B as specified in Annex IV without any readjustment to the fuelling between the two tests. However, one adaptation run over one ETC cycle without measurement is permitted after the change of the fuel. Before testing, the parent engine shall be run-in using the procedure defined in paragraph 3 of Appendix 2 to Annex III.

4.1.5.1.   The ratio of emission results ‘r’ shall be determined for each pollutant as follows:

4.2.   Granting of a fuel range restricted EC type-approval

Fuel range restricted EC type-approval is granted subject to the following requirements:

4.2.1.   Exhaust emissions approval of an engine running on natural gas and laid out for operation on either the range of H-gases or on the range of L-gases

The parent engine shall be tested on the relevant reference fuel, as specified in Annex IV, for the relevant range. The fuels are GR (fuel 1) and G23 (fuel 3) for the H-range of gases and G25 (fuel 2) and G23 (fuel 3) for the L-range of gases. The parent engine shall meet the requirements of this Directive without any readjustment to the fuelling between the two tests. However, one adaptation run over one ETC cycle without measurement is permitted after the change of the fuel. Before testing the parent engine shall be run-in using the procedure defined in paragraph 3 of Appendix 2 to Annex III.

4.2.1.1.   At the manufacturer's request the engine may be tested on a third fuel instead of G23 (fuel 3) if the λ-shift factor (Sλ) lies between 0,89 (i.e. the lower range of GR) and 1,19 (i.e. the upper range of G25), for example when fuel 3 is a market fuel. The results of this test may be used as a basis for the evaluation of the conformity of the production.

4.2.1.2.   The ratio of emission results ‘r’ shall be determined for each pollutant as follows:

or,

and,

4.2.1.3.   On delivery to the customer the engine shall bear a label (see paragraph 5.1.5) stating for which range of gases the engine is approved.

4.2.2.   Exhaust emissions approval of an engine running on natural gas or LPG and laid out for operation on one specific fuel composition

4.2.2.1.   The parent engine shall meet the emission requirements on the reference fuels GR and G25 in the case of natural gas, or the reference fuels A and B in the case of LPG, as specified in Annex IV. Between the tests fine-tuning of the fuelling system is allowed. This fine-tuning will consist of a recalibration of the fuelling database, without any alteration to either the basic control strategy or the basic structure of the database. If necessary the exchange of parts that are directly related to the amount of fuel flow (such as injector nozzles) is allowed.

4.2.2.2.   At the manufacturer's request the engine may be tested on the reference fuels GR and G23, or on the reference fuels G25 and G23, in which case the type-approval is only valid for the H-range or the L-range of gases respectively.

4.2.2.3.   On delivery to the customer the engine shall bear a label (see paragraph 5.1.5) stating for which fuel composition the engine has been calibrated.

4.3.   Exhaust emissions approval of a member of a family

4.3.1.   With the exception of the case mentioned in paragraph 4.3.2, the approval of a parent engine shall be extended to all family members without further testing, for any fuel composition within the range for which the parent engine has been approved (in the case of engines described in paragraph 4.2.2) or the same range of fuels (in the case of engines described in either paragraphs 4.1 or 4.2) for which the parent engine has been approved.

4.3.2.   Secondary test engine

In case of an application for type-approval of an engine, or a vehicle in respect of its engine, that engine belonging to an engine family, if the technical service determines that, with regard to the selected parent engine the submitted application does not fully represent the engine family defined in Annex I, Appendix 1, an alternative and if necessary an additional reference test engine may be selected by the technical service and tested.

4.4.   Type-approval certificate

A certificate conforming to the model specified in Annex VI shall be issued for approval referred to under Sections 3.1, 3.2 and 3.3.

5.   ENGINE MARKINGS

5.1.   The engine approved as a technical unit must bear:

5.1.1.   the trademark or trade name of the manufacturer of the engine;

5.1.2.   the manufacturer's commercial description;

5.1.3.   the EC type-approval number preceded by the distinctive letter(s) or number(s) of the country granting EC type-approval (4);

5.1.4.   in case of an NG engine one of the following markings to be placed after the EC type approval number:

5.1.5.   Labels

In the case of NG and LPG fuelled engines with a fuel range restricted type approval, the following labels are applicable:

5.1.5.1.   Content

The following information must be given:

In the case of paragraph 4.2.1.3, the label shall state

‘ONLY FOR USE WITH NATURAL GAS RANGE H’. If applicable, ‘H’ is replaced by ‘L’.

In the case of paragraph 4.2.2.3, the label shall state

‘ONLY FOR USE WITH NATURAL GAS SPECIFICATION …’ or ‘ONLY FOR USE WITH LIQUEFIED PETROLEUM GAS SPECIFICATION …’, as applicable. All the information in the appropriate table(s) in Annex IV shall be given with the individual constituents and limits specified by the engine manufacturer.

The letters and figures must be at least 4 mm in height.

Note:

If lack of space prevents such labelling, a simplified code may be used. In this event, explanatory notes containing all the above information must be easily accessible to any person filling the fuel tank or performing maintenance or repair on the engine and its accessories, as well as to the authorities concerned. The site and content of these explanatory notes will be determined by agreement between the manufacturer and the approval authority.

5.1.5.2.   Properties

Labels must be durable for the useful life of the engine. Labels must be clearly legible and their letters and figures must be indelible. Additionally, labels must be attached in such a manner that their fixing is durable for the useful life of the engine, and the labels cannot be removed without destroying or defacing them.

5.1.5.3.   Placing

Labels must be secured to an engine part necessary for normal engine operation and not normally requiring replacement during engine life. Additionally, these labels must be located so as to be readily visible to the average person after the engine has been completed with all the auxiliaries necessary for engine operation.

5.2.   In case of an application for EC type-approval for a vehicle type in respect of its engine, the marking specified in Section 5.1.5 shall also be placed close to fuel filling aperture.

5.3.   In case of an application for EC type-approval for a vehicle type with an approved engine, the marking specified in Section 5.1.5 shall also be placed close to the fuel filling aperture.

6.   SPECIFICATIONS AND TESTS

6.1.   General

6.1.1.   Emission control equipment

6.1.1.1.   The components liable to affect the emission of gaseous and particulate pollutants from diesel engines and the emission of gaseous pollutants from gas engines shall be so designed, constructed, assembled and installed as to enable the engine, in normal use, to comply with the provisions of this Directive.

6.1.2.   Functions of emission control equipment

6.1.2.1.   The use of a defeat device and/or an irrational emission control strategy is forbidden.

6.1.2.2.   An auxiliary control device may be installed to an engine, or on a vehicle, provided that the device:

6.1.2.3.   An engine control device, function, system or measure that operates during the conditions specified in Section 6.1.2.4 and which results in the use of a different or modified engine control strategy to that normally employed during the applicable emission test cycles will be permitted if, in complying with the requirements of Sections 6.1.3 and/or 6.1.4, it is fully demonstrated that the measure does not reduce the effectiveness of the emission control system. In all other cases, such devices shall be considered to be a defeat device.

6.1.2.4.   For the purposes of point 6.1.2.2, the defined conditions of use under steady state and transient conditions are:

6.1.3.   Special requirements for electronic emission control systems

6.1.3.1.   Documentation requirements

The manufacturer shall provide a documentation package that gives access to the basic design of the system and the means by which it controls its output variables, whether that control is direct or indirect.

The documentation shall be made available in two parts:

6.1.4.   To verify whether any strategy or measure should be considered a defeat device or an irrational emission control strategy according to the definitions given in Sections 2.29 and 2.31, the type-approval authority and/or the technical service may additionally request a NOx screening test using the ETC which may be carried out in combination with either the type-approval test or the procedures for checking the conformity of production.

6.1.4.1.   As an alternative to the requirements of Appendix 4 to Annex III the emissions of NOx during the ETC screening test may be sampled using the raw exhaust gas and the technical prescriptions of ISO DIS 16183, dated 15 October 2000, shall be followed.

6.1.4.2.   In verifying whether any strategy or measure should be considered a defeat device or an irrational emission control strategy according to the definitions given in Sections 2.29 and 2.31, an additional margin of 10 %, related to the appropriate NOx limit value, shall be accepted.

6.1.5.   Transitional provisions for extension of type-approval

6.1.5.1.   This section shall only be applicable to new compression-ignition engines and new vehicles propelled by a compression-ignition engine that have been type-approved to the requirements of row A of the tables in Section 6.2.1.

6.1.5.2.   As an alternative to Sections 6.1.3 and 6.1.4, the manufacturer may present to the technical service the results of a NOx screening test using the ETC on the engine conforming to the characteristics of the parent engine described in Annex II, and taking into account the provisions of Sections 6.1.4.1 and 6.1.4.2. The manufacturer shall also provide a written statement that the engine does not employ any defeat device or irrational emission control strategy as defined in Section 2 of this Annex.

6.1.5.3.   The manufacturer shall also provide a written statement that the results of the NOx screening test and the declaration for the parent engine, as referred to in Section 6.1.4, are also applicable to all engine types within the engine family described in Annex II.

6.2.   Specifications concerning the emission of gaseous and particulate pollutants and smoke

For type approval to row A of the tables in Section 6.2.1, the emissions shall be determined on the ESC and ELR tests with conventional diesel engines including those fitted with electronic fuel injection equipment, exhaust gas recirculation (EGR), and/or oxidation catalysts. Diesel engines fitted with advanced exhaust aftertreatment systems including the NOx catalysts and/or particulate traps, shall additionally be tested on the ETC test.

For type approval testing to either row B1 or B2 or row C of the tables in Section 6.2.1 the emissions shall be determined on the ESC, ELR and ETC tests.

For gas engines, the gaseous emissions shall be determined on the ETC test.

The ESC and ELR test procedures are described in Annex III, Appendix 1, the ETC test procedure in Annex III, Appendices 2 and 3.

The emissions of gaseous pollutants and particulate pollutants, if applicable, and smoke, if applicable, by the engine submitted for testing shall be measured by the methods described in Annex III, Appendix 4. Annex V describes the recommended analytical systems for the gaseous pollutants, the recommended particulate sampling systems, and the recommended smoke measurement system.

Other systems or analysers may be approved by the Technical Service if it is found that they yield equivalent results on the respective test cycle. The determination of system equivalency shall be based upon a 7 sample pair (or larger) correlation study between the system under consideration and one of the reference systems of this Directive. For particulate emissions only the full flow dilution system is recognised as the reference system. ‘Results’ refer to the specific cycle emissions value. The correlation testing shall be performed at the same laboratory, test cell, and on the same engine, and is preferred to be run concurrently. The equivalency criterion is defined as a ± 5 % agreement of the sample pair averages. For introduction of a new system into the Directive the determination of equivalency shall be based upon the calculation of repeatability and reproducibility, as described in ISO 5725.

6.2.1.   Limit values

The specific mass of the carbon monoxide, of the total hydrocarbons, of the oxides of nitrogen and of the particulates, as determined on the ESC test, and of the smoke opacity, as determined on the ELR test, shall not exceed the amounts shown in Table 1.

Table 1

Limit values — ESC and ELR tests

For diesel engines that are additionally tested on the ETC test, and specifically for gas engines, the specific masses of the carbon monoxide, of the non-methane hydrocarbons, of the methane (where applicable), of the oxides of nitrogen and of the particulates (where applicable) shall not exceed the amounts shown in Table 2.

Table 2

Limit values — ETC tests

6.2.2.   Hydrocarbon measurement for diesel and gas fuelled engines

6.2.2.1.   A manufacturer may choose to measure the mass of total hydrocarbons (THC) on the ETC test instead of measuring the mass of non-methane hydrocarbons. In this case, the limit for the mass of total hydrocarbons is the same as shown in Table 2 for the mass of non-methane hydrocarbons.

6.2.3.   Specific requirements for diesel engines

6.2.3.1.   The specific mass of the oxides of nitrogen measured at the random check points within the control area of the ESC test must not exceed by more than 10 per cent the values interpolated from the adjacent test modes (reference Annex III, Appendix 1, Sections 4.6.2 and 4.6.3).

6.2.3.2.   The smoke value on the random test speed of the ELR must not exceed the highest smoke value of the two adjacent test speeds by more than 20 per cent, or by more than 5 per cent of the limit value, whichever is greater.

7.   INSTALLATION ON THE VEHICLE

7.1.   The engine installation on the vehicle shall comply with the following characteristics in respect to the type-approval of the engine:

7.1.1.   intake depression shall not exceed that specified for the type-approved engine in Annex VI;

7.1.2.   exhaust back pressure shall not exceed that specified for the type-approved engine in Annex VI;

7.1.3.   the exhaust system volume shall not differ by more than 40 % of that specified for the type-approved engine in Annex VI;

7.1.4.   power absorbed by the auxiliaries needed for operating the engine shall not exceed that specified for the type-approved engine in Annex VI.

8.   ENGINE FAMILY

8.1.   Parameters defining the engine family

The engine family, as determined by the engine manufacturer, may be defined by basic characteristics which must be common to engines within the family. In some cases there may be interaction of parameters. These effects must also be taken into consideration to ensure that only engines with similar exhaust emission characteristics are included within an engine family.

In order that engines may be considered to belong to the same engine family, the following list of basic parameters must be common:

8.1.1.   Combustion cycle:

8.1.2.   Cooling medium:

8.1.3.   For gas engines and engines with aftertreatment:

(other diesel engines with fewer cylinders than the parent engine may be considered to belong to the same engine family provided the fuelling system meters fuel for each individual cylinder)

8.1.4.   Individual cylinder displacement:

8.1.5.   Method of air aspiration:

8.1.6.   Combustion chamber type/design:

8.1.7.   Valve and porting — configuration, size and number:

8.1.8.   Fuel injection system (diesel engines):

8.1.9.   Fuelling system (gas engines):

8.1.10.   Ignition system (gas engines)

8.1.11.   Miscellaneous features:

8.1.12.   Exhaust aftertreatment:

8.2.   Choice of the parent engine

8.2.1.   Diesel engines

The parent engine of the family shall be selected using the primary criteria of the highest fuel delivery per stroke at the declared maximum torque speed. In the event that two or more engines share this primary criteria, the parent engine shall be selected using the secondary criteria of highest fuel delivery per stroke at rated speed. Under certain circumstances, the approval authority may conclude that the worst case emission rate of the family can best be characterised by testing a second engine. Thus, the approval authority may select an additional engine for test based upon features which indicate that it may have the highest emission level of the engines within that family.

If engines within the family incorporate other variable features which could be considered to affect exhaust emissions, these features shall also be identified and taken into account in the selection of the parent engine.

8.2.2.   Gas engines

The parent engine of the family shall be selected using the primary criteria of the largest displacement. In the event that two or more engines share this primary criteria, the parent engine shall be selected using the secondary criteria in the following order:

Under certain circumstances, the approval authority may conclude that the worst case emission rate of the family can best be characterised by testing a second engine. Thus, the approval authority may select an additional engine for test based upon features which indicate that it may have the highest emission level of the engines within that family.

9.   PRODUCTION CONFORMITY

9.1.   Measures to ensure production conformity must be taken in accordance with the provisions of Article 10 of Directive 70/156/EEC. Production conformity is checked on the basis of the description in the type-approval certificates set out in Annex VI to this Directive.

Sections 2.4.2 and 2.4.3 of Annex X to Directive 70/156/EEC are applicable where the competent authorities are not satisfied with the auditing procedure of the manufacturer.

9.1.1.   If emissions of pollutants are to be measured and an engine type-approval has had one or several extensions, the tests will be carried out on the engine(s) described in the information package relating to the relevant extension.

9.1.1.1.   Conformity of the engine subjected to a pollutant test:

After submission of the engine to the authorities, the manufacturer shall not carry out any adjustment to the engines selected.

9.1.1.1.1.   Three engines are randomly taken in the series. Engines that are subject to testing only on the ESC and ELR tests or only on the ETC test for type approval to row A of the tables in Section 6.2.1 are subject to those applicable tests for the checking of production conformity. With the agreement of the authority, all other engines type approved to row A, B1 or B2, or C of the tables in Section 6.2.1 are subjected to testing either on the ESC and ELR cycles or on the ETC cycle for the checking of the production conformity. The limit values are given in Section 6.2.1 of this Annex.

9.1.1.1.2.   The tests are carried out according to Appendix 1 to this Annex, where the competent authority is satisfied with the production standard deviation given by the manufacturer, in accordance with Annex X to Directive 70/156/EEC, which applies to motor vehicles and their trailers.

The tests are carried out according to Appendix 2 to this Annex, where the competent authority is not satisfied with the production standard deviation given by the manufacturer, in accordance with Annex X to Directive 70/156/EEC, which applies to motor vehicles and their trailers.

At the manufacturer's request, the tests may be carried out in accordance with Appendix 3 to this Annex.

9.1.1.1.3.   On the basis of a test of the engine by sampling, the production of a series is regarded as conforming where a pass decision is reached for all the pollutants and non-conforming where a fail decision is reached for one pollutant, in accordance with the test criteria applied in the appropriate Appendix.

When a pass decision has been reached for one pollutant, this decision may not be changed by any additional tests made in order to reach a decision for the other pollutants.

If no pass decision is reached for all the pollutants and if no fail decision is reached for one pollutant, a test is carried out on another engine (see Figure 2).

If no decision is reached, the manufacturer may at any time decide to stop testing. In that case a fail decision is recorded.

9.1.1.2.   The tests will be carried out on newly manufactured engines. Gas fuelled engines shall be run-in using the procedure defined in paragraph 3 of Appendix 2 to Annex III.

9.1.1.2.1.   However, at the request of the manufacturer, the tests may be carried out on diesel or gas engines which have been run-in more than the period referred to in Section 9.1.1.2, up to a maximum of 100 hours. In this case, the running-in procedure will be conducted by the manufacturer who shall undertake not to make any adjustments to those engines.

9.1.1.2.2.   When the manufacturer asks to conduct a running-in procedure in accordance with Section 9.1.1.2.1, it may be carried out on:

The subsequent test engines will not be subjected to the running-in procedure, but their zero hour emissions will be modified by the evolution coefficient.

In this case, the values to be taken will be:

9.1.1.2.3.   For diesel and LPG fuelled engines, all these tests may be conducted with commercial fuel. However, at the manufacturer's request, the reference fuels described in Annex IV may be used. This implies tests, as described in Section 4 of this Annex, with at least two of the reference fuels for each gas engine.

9.1.1.2.4.   For NG fuelled engines, all these tests may be conducted with commercial fuel in the following way:

However, at the manufacturer's request, the reference fuels described in Annex IV may be used. This implies tests, as described in Section 4 of this Annex.

9.1.1.2.5.   In the case of dispute caused by the non-compliance of gas fuelled engines when using a commercial fuel, the tests shall be performed with a reference fuel on which the parent engine has been tested, or with the possible additional fuel 3 as referred to in paragraphs 4.1.3.1 and 4.2.1.1 on which the parent engine may have been tested. Then, the result has to be converted by a calculation applying the relevant factor(s) ‘r’, ‘ra’ or ‘rb’ as described in paragraphs 4.1.4, 4.1.5.1 and 4.2.1.2. If r, ra or rb are less than 1 no correction shall take place. The measured results and the calculated results must demonstrate that the engine meets the limit values with all relevant fuels (fuels 1, 2 and, if applicable, fuel 3 in the case of natural gas engines and fuels A and B in the case of LPG engines).

9.1.1.2.6.   Tests for conformity of production of a gas fuelled engine laid out for operation on one specific fuel composition shall be performed on the fuel for which the engine has been calibrated.

(1)  OJ L 76, 6.4.1970, p. 1. Directive as last amended by Commission Directive 2003/76/EC (OJ L 206, 15.8.2003, p. 29).

(2)  OJ L 375, 31.12.1980, p. 46. Directive as last amended by Commission Directive 1999/99/EC (OJ L 334, 28.12.1999, p. 32).

(3)  OJ L 42, 23.2.1970, p. 1. Directive as last amended by Commission Directive 2004/104/EC (OJ L 337, 13.11.2004, p. 13).

(4)  1 = Germany, 2 = France, 3 = Italy, 4 = Netherlands, 5 = Sweden, 6 = Belgium, 7 = Hungary, 8 = Czech Republic, 9 = Spain, 11 = United Kingdom, 12 = Austria, 13 = Luxembourg, 17 = Finland, 18 = Denmark, 20 = Poland, 21 = Portugal, 23 = Greece, 24 = Ireland, 26 = Slovenia, 27 = Slovakia, 29 = Estonia, 32 = Latvia, 36 = Lithuania, 49 = Cyprus, 50 = Malta.

(5)  For engines having a swept volume of less than 0,75 dm3 per cylinder and a rated power speed of more than 3 000 min -1.

(6)  For NG engines only.

(7)  Not applicable for gas fuelled engines at stage A and stages B1 and B2.

(8)  For engines having a swept volume of less than 0,75 dm3 per cylinder and a rated power speed of more than 3 000 min-1.

Appendix 1

PROCEDURE FOR PRODUCTION CONFORMITY TESTING WHEN STANDARD DEVIATION IS SATISFACTORY

1.	This Appendix describes the procedure to be used to verify production conformity for the emissions of pollutants when the manufacturer's production standard deviation is satisfactory.

2.

With a minimum sample size of three engines the sampling procedure is set so that the probability of a lot passing a test with 40 % of the engines defective is 0,95 (producer's risk = 5 %) while the probability of a lot being accepted with 65 % of the engines defective is 0,10 (consumer's risk = 10 %).

3.

The following procedure is used for each of the pollutants given in Section 6.2.1 of Annex I (see Figure 2):   Let:   L = the natural logarithm of the limit value for the pollutant; χi = the natural logarithm of the measurement for the i-th engine of the sample; s = an estimate of the production standard deviation (after taking the natural logarithm of the measurements); n = the current sample number.

4.	For each sample the sum of the standardised deviations to the limit is calculated using the following formula:

5.

Then: — if the test statistic result is greater than the pass decision number for the sample size given in Table 3, a pass decision is reached for the pollutant; — if the test statistic result is less than the fail decision number for the sample size given in Table 3, a fail decision is reached for the pollutant; — otherwise, an additional engine is tested according to Section 9.1.1.1 of Annex I and the calculation procedure is applied to the sample increased by one more unit.

Table 3

Pass and fail decision numbers of Appendix 1 sampling plan

Minimum sample size: 3

Cumulative number of engines tested (sample size)	Pass decision number An	Fail decision number Bn
3	3,327	– 4,724
4	3,261	– 4,790
5	3,195	– 4,856
6	3,129	– 4,922
7	3,063	– 4,988
8	2,997	– 5,054
9	2,931	– 5,120
10	2,865	– 5,185
11	2,799	– 5,251
12	2,733	– 5,317
13	2,667	– 5,383
14	2,601	– 5,449
15	2,535	– 5,515
16	2,469	– 5,581
17	2,403	– 5,647
18	2,337	– 5,713
19	2,271	– 5,779
20	2,205	– 5,845
21	2,139	– 5,911
22	2,073	– 5,977
23	2,007	– 6,043
24	1,941	– 6,109
25	1,875	– 6,175
26	1,809	– 6,241
27	1,743	– 6,307
28	1,677	– 6,373
29	1,611	– 6,439
30	1,545	– 6,505
31	1,479	– 6,571
32	– 2,112	– 2,112

Appendix 2

PROCEDURE FOR PRODUCTION CONFORMITY TESTING WHEN STANDARD DEVIATION IS UNSATISFACTORY OR UNAVAILABLE

1.	This Appendix describes the procedure to be used to verify production conformity for the emissions of pollutants when the manufacturer's production standard deviation is either unsatisfactory or unavailable.

2.

With a minimum sample size of three engines the sampling procedure is set so that the probability of a lot passing a test with 40 % of the engines defective is 0,95 (producer's risk = 5 %) while the probability of a lot being accepted with 65 % of the engines defective is 0,10 (consumer's risk = 10 %).

3.

The values of the pollutants given in Section 6.2.1 of Annex I are considered to be log normally distributed and should be transformed by taking their natural logarithms. Let m0 and m denote the minimum and maximum sample size respectively (m0 = 3 and m = 32) and let n denote the current sample number.

4.	If the natural logarithms of the values measured in the series are χ1, χ2, … χi and L is the natural logarithm of the limit value for the pollutant, then, define and

5.

Table 4 shows values of the pass (An) and fail (Bn) decision numbers against current sample number. The test statistic result is the ratio: and shall be used to determine whether the series has passed or failed as follows: for m0 ≤ n < m: — pass the series if , — fail the series if , — take another measurement if .

6.	Remarks The following recursive formulae are useful for calculating successive values of the test statistic:

Table 4

Pass and fail decision numbers of Appendix 2 sampling plan

Minimum sample size: 3

Cumulative number of engines tested (sample size)	Pass decision number An	Fail decision number Bn
3	- 0,80381	16,64743
4	- 0,76339	7,68627
5	- 0,72982	4,67136
6	- 0,69962	3,25573
7	- 0,67129	2,45431
8	- 0,64406	1,94369
9	- 0,61750	1,59105
10	- 0,59135	1,33295
11	- 0,56542	1,13566
12	- 0,53960	0,97970
13	- 0,51379	0,85307
14	- 0,48791	0,74801
15	- 0,46191	0,65928
16	- 0,43573	0,58321
17	- 0,40933	0,51718
18	- 0,38266	0,45922
19	- 0,35570	0,40788
20	- 0,32840	0,36203
21	- 0,30072	0,32078
22	- 0,27263	0,28343
23	- 0,24410	0,24943
24	- 0,21509	0,21831
25	- 0,18557	0,18970
26	- 0,15550	0,16328
27	- 0,12483	0,13880
28	- 0,09354	0,11603
29	- 0,06159	0,09480
30	- 0,02892	0,07493
31	- 0,00449	0,05629
32	- 0,03876	0,03876

ANNEX II

(1)  Delete as appropriate.

ANNEX III

TEST PROCEDURE

1.   INTRODUCTION

1.3.   Measurement principle

The emissions to be measured from the exhaust of the engine include the gaseous components (carbon monoxide, total hydrocarbons for diesel engines on the ESC test only; non-methane hydrocarbons for diesel and gas engines on the ETC test only; methane for gas engines on the ETC test only and oxides of nitrogen), the particulates (diesel engines only) and smoke (diesel engines on the ELR test only). Additionally, carbon dioxide is often used as a tracer gas for determining the dilution ratio of partial and full flow dilution systems. Good engineering practice recommends the general measurement of carbon dioxide as an excellent tool for the detection of measurement problems during the test run.

1.3.1.   ESC test

During a prescribed sequence of warmed-up engine operating conditions the amounts of the above exhaust emissions shall be examined continuously by taking a sample from the raw exhaust gas. The test cycle consists of a number of speed and power modes which cover the typical operating range of diesel engines. During each mode the concentration of each gaseous pollutant, exhaust flow and power output shall be determined, and the measured values weighted. The particulate sample shall be diluted with conditioned ambient air. One sample over the complete test procedure shall be taken, and collected on suitable filters. The grams of each pollutant emitted per kilowatt hour shall be calculated as described in Appendix 1 to this Annex. Additionally, NOx shall be measured at three test points within the control area selected by the Technical Service (1) and the measured values compared to the values calculated from those modes of the test cycle enveloping the selected test points. The NOx control check ensures the effectiveness of the emission control of the engine within the typical engine operating range.

1.3.2.   ELR test

During a prescribed load response test, the smoke of a warmed-up engine shall be determined by means of an opacimeter. The test consists of loading the engine at constant speed from 10 % to 100 % load at three different engine speeds. Additionally, a fourth load step selected by the Technical Service (1) shall be run, and the value compared to the values of the previous load steps. The smoke peak shall be determined using an averaging algorithm, as described in Appendix 1 to this Annex.

1.3.3.   ETC test

During a prescribed transient cycle of warmed-up engine operating conditions, which is based closely on road-type-specific driving patterns of heavy-duty engines installed in trucks and buses, the above pollutants shall be examined after diluting the total exhaust gas with conditioned ambient air. Using the engine torque and speed feedback signals of the engine dynamometer, the power shall be integrated with respect to time of the cycle resulting in the work produced by the engine over the cycle. The concentration of NOx and HC shall be determined over the cycle by integration of the analyser signal. The concentration of CO, CO2, and NMHC may be determined by integration of the analyser signal or by bag sampling. For particulates, a proportional sample shall be collected on suitable filters. The diluted exhaust gas flow rate shall be determined over the cycle to calculate the mass emission values of the pollutants. The mass emission values shall be related to the engine work to get the grams of each pollutant emitted per kilowatt hour, as described in Appendix 2 to this Annex.

2.   TEST CONDITIONS

2.1.   Engine test conditions

2.1.1.

The absolute temperature (Ta) of the engine air at the inlet to the engine expressed in Kelvin, and the dry atmospheric pressure (ps), expressed in kPa shall be measured and the parameter F shall be determined according to the following provisions: (a) for diesel engines:   Naturally aspirated and mechanically supercharged engines:   Turbocharged engines with or without cooling of the intake air: (b) for gas engines:

2.1.2.   Test validity

For a test to be recognised as valid, the parameter F shall be such that:

2.2.   Engines with charge air cooling

The charge air temperature shall be recorded and shall be, at the speed of the declared maximum power and full load, within ± 5 K of the maximum charge air temperature specified in Annex II, Appendix 1, Section 1.16.3. The temperature of the cooling medium shall be at least 293 K (20 °C).

If a test shop system or external blower is used, the charge air temperature shall be within ± 5 K of the maximum charge air temperature specified in Annex II, Appendix 1, Section 1.16.3 at the speed of the declared maximum power and full load. The setting of the charge air cooler for meeting the above conditions shall be used for the whole test cycle.

2.3.   Engine air intake system

An engine air intake system shall be used presenting an air intake restriction within ± 100 Pa of the upper limit of the engine operating at the speed at the declared maximum power and full load.

2.4.   Engine exhaust system

An exhaust system shall be used presenting an exhaust back pressure within ± 1 000 Pa of the upper limit of the engine operating at the speed of declared maximum power and full load and a volume within ± 40 % of that specified by the manufacturer. A test shop system may be used, provided it represents actual engine operating conditions. The exhaust system shall conform to the requirements for exhaust gas sampling, as set out in Annex III, Appendix 4, Section 3.4 and in Annex V, Section 2.2.1, EP and Section 2.3.1, EP.

If the engine is equipped with an exhaust aftertreatment device, the exhaust pipe must have the same diameter as found in-use for at least 4 pipe diameters upstream to the inlet of the beginning of the expansion section containing the aftertreatment device. The distance from the exhaust manifold flange or turbocharger outlet to the exhaust aftertreatment device shall be the same as in the vehicle configuration or within the distance specifications of the manufacturer. The exhaust backpressure or restriction shall follow the same criteria as above, and may be set with a valve. The aftertreatment container may be removed during dummy tests and during engine mapping, and replaced with an equivalent container having an inactive catalyst support.

2.5.   Cooling system

An engine cooling system with sufficient capacity to maintain the engine at normal operating temperatures prescribed by the manufacturer shall be used.

2.6.   Lubricating oil

Specifications of the lubricating oil used for the test shall be recorded and presented with the results of the test, as specified in Annex II, Appendix 1, Section 7.1.

2.7.   Fuel

The fuel shall be the reference fuel specified in Annex IV.

The fuel temperature and measuring point shall be specified by the manufacturer within the limits given in Annex II, Appendix 1, Section 1.16.5. The fuel temperature shall not be lower than 306 K (33 °C). If not specified, it shall be 311 K ± 5 K (38 °C ± 5 °C) at the inlet to the fuel supply.

For NG and LPG fuelled engines, the fuel temperature and measuring point shall be within the limits given in Annex II, Appendix 1, Section 1.16.5 or in Annex II, Appendix 3, Section 1.16.5 in cases where the engine is not a parent engine.

2.8.   Testing of exhaust aftertreatment systems

If the engine is equipped with an exhaust aftertreatment system, the emissions measured on the test cycle(s) shall be representative of the emissions in the field. If this cannot be achieved with one single test cycle (e.g. for particulate filters with periodic regeneration), several test cycles shall be conducted and the test results averaged and/or weighted. The exact procedure shall be agreed by the engine manufacturer and the Technical Service based upon good engineering judgement.

(1)  The test points shall be selected using approved statistical methods of randomisation.

Appendix 1

ESC AND ELR TEST CYCLES

1.   ENGINE AND DYNAMOMETER SETTINGS

1.1.   Determination of engine speeds A, B and C

The engine speeds A, B and C shall be declared by the manufacturer in accordance with the following provisions:

The high speed nhi shall be determined by calculating 70 % of the declared maximum net power P(n), as determined in Annex II, Appendix 1, Section 8.2. The highest engine speed where this power value occurs on the power curve is defined as nhi.

The low speed nlo shall be determined by calculating 50 % of the declared maximum net power P(n), as determined in Annex II, Appendix 1, Section 8.2. The lowest engine speed where this power value occurs on the power curve is defined as nlo.

The engine speeds A, B and C shall be calculated as follows:

The engine speeds A, B and C may be verified by either of the following methods:

(a)

additional test points shall be measured during engine power approval according to Directive 80/1269/EEC for an accurate determination of nhi and nlo. The maximum power, nhi and nlo shall be determined from the power curve, and engine speeds A, B and C shall be calculated according to the above provisions;

b)

the engine shall be mapped along the full load curve, from maximum no load speed to idle speed, using at least 5 measurement points per 1 000 rpm intervals and measurement points within ± 50 rpm of the speed at declared maximum power. The maximum power, nhi and nlo shall be determined from this mapping curve, and engine speeds A, B and C shall be calculated according to the above provisions.

If the measured engine speeds A, B and C are within ± 3 % of the engine speeds as declared by the manufacturer, the declared engine speeds shall be used for the emissions test. If the tolerance is exceeded for any of the engine speeds, the measured engine speeds shall be used for the emissions test.

1.2.   Determination of dynamometer settings

The torque curve at full load shall be determined by experimentation to calculate the torque values for the specified test modes under net conditions, as specified in Annex II, Appendix 1, Section 8.2. The power absorbed by engine-driven equipment, if applicable, shall be taken into account. The dynamometer setting for each test mode shall be calculated using the formula:

if tested under net conditions

if not tested under net conditions

where:

s	=	dynamometer setting, kW
P(n)	=	net engine power as indicated in Annex II, Appendix 1, Section 8.2, kW
L	=	per cent load as indicated in Section 2.7.1, %
P(a)	=	power absorbed by auxiliaries to be fitted as indicated in Annex II, Appendix 1, Section 6.1
P(b)	=	power absorbed by auxiliaries to be removed as indicated in Annex II, Appendix 1, Section 6.2

2.   ESC TEST RUN

At the manufacturers request, a dummy test may be run for conditioning of the engine and exhaust system before the measurement cycle.

2.1.   Preparation of the sampling filters

At least one hour before the test, each filter (pair) shall be placed in a closed, but unsealed petri dish and placed in a weighing chamber for stabilisation. At the end of the stabilisation period, each filter (pair) shall be weighed and the tare weight shall be recorded. The filter (pair) shall then be stored in a closed Petri dish or sealed filter holder until needed for testing. If the filter (pair) is not used within eight hours of its removal from the weighing chamber, it must be conditioned and reweighed before use.

2.2.   Installation of the measuring equipment

The instrumentation and sample probes shall be installed as required. When using a full flow dilution system for exhaust gas dilution, the tailpipe shall be connected to the system.

2.3.   Starting the dilution system and the engine

The dilution system and the engine shall be started and warmed up until all temperatures and pressures have stabilised at maximum power according to the recommendation of the manufacturer and good engineering practice.

2.4.   Starting the particulate sampling system

The particulate sampling system shall be started and running on by-pass. The particulate background level of the dilution air may be determined by passing dilution air through the particulate filters. If filtered dilution air is used, one measurement may be done prior to or after the test. If the dilution air is not filtered, measurements at the beginning and at the end of the cycle, may be done, and the values averaged.

2.5.   Adjustment of the dilution ratio

The dilution air shall be set such that the temperature of the diluted exhaust gas measured immediately prior to the primary filter shall not exceed 325 K (52 °C) at any mode. The dilution ratio (q) shall not be less than 4.

For systems that use CO2 or NOx concentration measurement for dilution ratio control, the CO2 or NOx content of the dilution air must be measured at the beginning and at the end of each test. The pre- and post-test background CO2 or NOx concentration measurements of the dilution air must be within 100 ppm or 5 ppm of each other, respectively.

2.6.   Checking the analysers

The emission analysers shall be set at zero and spanned.

2.7.   Test cycle

2.7.1.   The following 13-mode cycle shall be followed in dynamometer operation on the test engine

Mode number	Engine speed	Percent load	Weighting factor	Mode length
1	idle	—	0,15	4 minutes
2	A	100	0,08	2 minutes
3	B	50	0,10	2 minutes
4	B	75	0,10	2 minutes
5	A	50	0,05	2 minutes
6	A	75	0,05	2 minutes
7	A	25	0,05	2 minutes
8	B	100	0,09	2 minutes
9	B	25	0,10	2 minutes
10	C	100	0,08	2 minutes
11	C	25	0,05	2 minutes
12	C	75	0,05	2 minutes
13	C	50	0,05	2 minutes

2.7.2.   Test sequence

The test sequence shall be started. The test shall be performed in the order of the mode numbers as set out in Section 2.7.1.

The engine must be operated for the prescribed time in each mode, completing engine speed and load changes in the first 20 seconds. The specified speed shall be held to within ± 50 rpm and the specified torque shall be held to within ± 2 % of the maximum torque at the test speed.

At the manufacturers request, the test sequence may be repeated a sufficient number of times for sampling more particulate mass on the filter. The manufacturer shall supply a detailed description of the data evaluation and calculation procedures. The gaseous emissions shall only be determined on the first cycle.

2.7.3.   Analyser response

The output of the analysers shall be recorded on a strip chart recorder or measured with an equivalent data acquisition system with the exhaust gas flowing through the analysers throughout the test cycle.

2.7.4.   Particulate sampling

One pair of filters (primary and back-up filters, see Annex III, Appendix 4) shall be used for the complete test procedure. The modal weighting factors specified in the test cycle procedure shall be taken into account by taking a sample proportional to the exhaust mass flow during each individual mode of the cycle. This can be achieved by adjusting sample flow rate, sampling time, and/or dilution ratio, accordingly, so that the criterion for the effective weighting factors in Section 5.6 is met.

The sampling time per mode must be at least 4 seconds per 0,01 weighting factor. Sampling must be conducted as late as possible within each mode. Particulate sampling shall be completed no earlier than 5 seconds before the end of each mode.

2.7.5.   Engine conditions

The engine speed and load, intake air temperature and depression, exhaust temperature and backpressure, fuel flow and air or exhaust flow, charge air temperature, fuel temperature and humidity shall be recorded during each mode, with the speed and load requirements (see Section 2.7.2) being met during the time of particulate sampling, but in any case during the last minute of each mode.

Any additional data required for calculation shall be recorded (see Sections 4 and 5).

2.7.6.   NOx check within the control area

The NOx check within the control area shall be performed immediately upon completion of mode 13.

The engine shall be conditioned at mode 13 for a period of three minutes before the start of the measurements. Three measurements shall be made at different locations within the control area, selected by the Technical Service (1). The time for each measurement shall be 2 minutes.

The measurement procedure is identical to the NOx measurement on the 13-mode cycle, and shall be carried out in accordance with Sections 2.7.3, 2.7.5, and 4.1 of this Appendix, and Annex III, Appendix 4, Section 3.

The calculation shall be carried out in accordance with Section 4.

2.7.7.   Rechecking the analysers

After the emission test a zero gas and the same span gas shall be used for rechecking. The test will be considered acceptable if the difference between the pre-test and post-test results is less than 2 % of the span gas value.

3.   ELR TEST RUN

3.1.   Installation of the measuring equipment

The opacimeter and sample probes, if applicable, shall be installed after the exhaust silencer or any aftertreatment device, if fitted, according to the general installation procedures specified by the instrument manufacturer. Additionally, the requirements of Section 10 of ISO IDS 11614 shall be observed, where appropriate.

Prior to any zero and full scale checks, the opacimeter shall be warmed up and stabilised according to the instrument manufacturer's recommendations. If the opacimeter is equipped with a purge air system to prevent sooting of the meter optics, this system shall also be activated and adjusted according to the manufacturer's recommendations.

3.2.   Checking of the opacimeter

The zero and full scale checks shall be made in the opacity readout mode, since the opacity scale offers two truly definable calibration points, namely 0 % opacity and 100 % opacity. The light absorption coefficient is then correctly calculated based upon the measured opacity and the LA, as submitted by the opacimeter manufacturer, when the instrument is returned to the k readout mode for testing.

With no blockage of the opacimeter light beam, the readout shall be adjusted to 0,0 % ± 1,0 % opacity. With the light being prevented from reaching the receiver, the readout shall be adjusted to 100,0 % ± 1,0 % opacity.

3.3.   Test cycle

3.3.1.   Conditioning of the engine

Warming up of the engine and the system shall be at maximum power in order to stabilise the engine parameters according to the recommendation of the manufacturer. The preconditioning phase should also protect the actual measurement against the influence of deposits in the exhaust system from a former test.

When the engine is stabilised, the cycle shall be started within 20 ± 2 s after the preconditioning phase. At the manufacturers request, a dummy test may be run for additional conditioning before the measurement cycle.

3.3.2.   Test sequence

The test consists of a sequence of three load steps at each of the three engine speeds A (cycle 1), B (cycle 2) and C (cycle 3) determined in accordance with Annex III, Section 1.1, followed by cycle 4 at a speed within the control area and a load between 10 % and 100 %, selected by the Technical Service (2). The following sequence shall be followed in dynamometer operation on the test engine, as shown in Figure 3.

(a)	The engine shall be operated at engine speed A and 10 per cent load for 20 ± 2 s. The specified speed shall be held to within ± 20 rpm and the specified torque shall be held to within ± 2 % of the maximum torque at the test speed.

(b)

At the end of the previous segment, the speed control lever shall be moved rapidly to, and held in, the wide open position for 10 ± 1 s. The necessary dynamometer load shall be applied to keep the engine speed within ± 150 rpm during the first 3 s, and within ± 20 rpm during the rest of the segment.

(c)	The sequence described in (a) and (b) shall be repeated two times.

(d)	Upon completion of the third load step, the engine shall be adjusted to engine speed B and 10 per cent load within 20 ± 2 s.

(e)	The sequence (a) to (c) shall be run with the engine operating at engine speed B.

(f)	Upon completion of the third load step, the engine shall be adjusted to engine speed C and 10 per cent load within 20 ± 2 s.

(g)	The sequence (a) to (c) shall be run with the engine operating at engine speed C.

(h)	Upon completion of the third load step, the engine shall be adjusted to the selected engine speed and any load above 10 per cent within 20 ± 2 s.

(i)	The sequence (a) to (c) shall be run with the engine operating at the selected engine speed.

3.4.   Cycle validation

The relative standard deviations of the mean smoke values at each test speed (SVA, SVB, SVC, as calculated in accordance with Section 6.3.3 of this Appendix from the three successive load steps at each test speed) shall be lower than 15 % of the mean value, or 10 % of the limit value shown in Table 1 of Annex I, whichever is greater. If the difference is greater, the sequence shall be repeated until three successive load steps meet the validation criteria.

3.5.   Rechecking of the opacimeter

The post-test opacimeter zero drift value shall not exceed ± 5,0 % of the limit value shown in Table 1 of Annex I.

4.   CALCULATION OF THE GASEOUS EMISSIONS

4.1.   Data evaluation

For the evaluation of the gaseous emissions, the chart reading of the last 30 seconds of each mode shall be averaged, and the average concentrations (conc) of HC, CO and NOx during each mode shall be determined from the average chart readings and the corresponding calibration data. A different type of recording can be used if it ensures an equivalent data acquisition.

For the NOx check within the control area, the above requirements apply for NOx, only.

The exhaust gas flow GEXHW or the diluted exhaust gas flow GTOTW, if used optionally, shall be determined in accordance with Annex III, Appendix 4, Section 2.3.

4.2.   Dry/wet correction

The measured concentration shall be converted to a wet basis according to the following formulae, if not already measured on a wet basis.

For the raw exhaust gas:

and,

For the diluted exhaust gas:

or,

For the dilution air	For the intake air (if different from the dilution air)

where:

Ha, Hd	=	g water per kg dry air
Rd, Ra	=	relative humidity of the dilution/intake air, %
pd, pa	=	saturation vapour pressure of the dilution/intake air, kPa
pB	=	total barometric pressure, kPa

4.3.   NOx correction for humidity and temperature

As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for ambient air temperature and humidity with the factors given in the following formulae:

with:

A	=	0,309 GFUEL/GAIRD - 0,0266
B	=	- 0,209 GFUEL/GAIRD + 0,00954
Ta	=	temperature of the air, K
Ha	=	humidity of the intake air, g water per kg dry air
Ha	=

in which

Ra	=	relative humidity of the intake air, %
pa	=	saturation vapour pressure of the intake air, kPa
pB	=	total barometric pressure, kPa

4.4.   Calculation of the emission mass flow rates

The emission mass flow rates (g/h) for each mode shall be calculated as follows, assuming the exhaust gas density to be 1,293 kg/m3 at 273 K (0 C) and 101,3 kPa:

where NOx conc, COconc, HCconc  (3) are the average concentrations (ppm) in the raw exhaust gas, as determined in Section 4.1.

If, optionally, the gaseous emissions are determined with a full flow dilution system, the following formulae shall be applied:

where NOx conc, COconc, HCconc  (3) are the average background corrected concentrations (ppm) of each mode in the diluted exhaust gas, as determined in Annex III, Appendix 2, Section 4.3.1.1.

4.5.   Calculation of the specific emissions

The emissions (g/kWh) shall be calculated for all individual components in the following way:

The weighting factors (WF) used in the above calculation are according to Section 2.7.1.

4.6.   Calculation of the area control values

For the three control points selected according to Section 2.7.6, the NOx emission shall be measured and calculated according to Section 4.6.1 and also determined by interpolation from the modes of the test cycle closest to the respective control point according to Section 4.6.2. The measured values are then compared to the interpolated values according to Section 4.6.3.

4.6.1.   Calculation of the specific emission

The NOx emission for each of the control points (Z) shall be calculated as follows:

4.6.2.   Determination of the emission value from the test cycle

The NOx emission for each of the control points shall be interpolated from the four closest modes of the test cycle that envelop the selected control point Z as shown in Figure 4. For these modes (R, S, T, U), the following definitions apply:

Speed(R)	=	Speed(T) = nRT
Speed(S)	=	Speed(U) = nSU
Per cent load(R)	=	Per cent load(S)
Per cent load(T)	=	Per cent load(U).

The NOx emission of the selected control point Z shall be calculated as follows:

and:

where,

ER, ES, ET, EU	=	specific NOx emission of the enveloping modes calculated in accordance with Section 4.6.1.
MR, MS, MT, MU	=	engine torque of the enveloping modes

4.6.3.   Comparison of NOx emission values

The measured specific NOx emission of the control point Z (NOx,Z) is compared to the interpolated value (EZ) as follows:

5.   CALCULATION OF THE PARTICULATE EMISSION

5.1.   Data evaluation

For the evaluation of the particulates, the total sample masses (MSAM,i) through the filters shall be recorded for each mode.

The filters shall be returned to the weighing chamber and conditioned for at least one hour, but not more than 80 hours, and then weighed. The gross weight of the filters shall be recorded and the tare weight (see Section 1 of this Appendix) subtracted. The particulate mass Mf is the sum of the particulate masses collected on the primary and back-up filters.

If background correction is to be applied, the dilution air mass (MDIL) through the filters and the particulate mass (Md) shall be recorded. If more than one measurement was made, the quotient Md/MDIL must be calculated for each single measurement and the values averaged.

5.2.   Partial flow dilution system

The final reported test results of the particulate emission shall be determined through the following steps. Since various types of dilution rate control may be used, different calculation methods for GEDFW apply. All calculations shall be based upon the average values of the individual modes during the sampling period.

5.2.1.   Isokinetic systems

where r corresponds to the ratio of the cross-sectional areas of the isokinetic probe and the exhaust pipe:

5.2.2.   Systems with measurement of CO2 or NOx concentration

where:

concE	=	wet concentration of the tracer gas in the raw exhaust
concD	=	wet concentration of the tracer gas in the diluted exhaust
concA	=	wet concentration of the tracer gas in the dilution air

Concentrations measured on a dry basis shall be converted to a wet basis according to Section 4.2 of this Appendix.

5.2.3.   Systems with CO2 measurement and carbon balance method (4)

where:

CO2D	=	CO2 concentration of the diluted exhaust
CO2A	=	CO2 concentration of the dilution air

(concentrations in vol % on wet basis)

This equation is based upon the carbon balance assumption (carbon atoms supplied to the engine are emitted as CO2) and determined through the following steps:

and

5.2.4.   Systems with flow measurement

5.3.   Full flow dilution system

The reported test results of the particulate emission shall be determined through the following steps. All calculations shall be based upon the average values of the individual modes during the sampling period.

5.4.   Calculation of the particulate mass flow rate

The particulate mass flow rate shall be calculated as follows:

where

=

MSAM=

i=

determined over the test cycle by summation of the average values of the individual modes during the sampling period.

The particulate mass flow rate may be background corrected as follows:

If more than one measurement is made, shall be replaced with .

for the individual modes

or,

for the individual modes.

5.5.   Calculation of the specific emission

The particulate emission shall be calculated in the following way:

5.6.   Effective weighting factor

The effective weighting factor WFE,i for each mode shall be calculated in the following way:

The value of the effective weighting factors shall be within ± 0,003 (± 0,005 for the idle mode) of the weighting factors listed in Section 2.7.1.

6.   CALCULATION OF THE SMOKE VALUES

6.1.   Bessel algorithm

The Bessel algorithm shall be used to compute the 1 s average values from the instantaneous smoke readings, converted in accordance with Section 6.3.1. The algorithm emulates a low pass second order filter, and its use requires iterative calculations to determine the coefficients. These coefficients are a function of the response time of the opacimeter system and the sampling rate. Therefore, Section 6.1.1 must be repeated whenever the system response time and/or sampling rate changes.

6.1.1.   Calculation of filter response time and Bessel constants

The required Bessel response time (tF) is a function of the physical and electrical response times of the opacimeter system, as specified in Annex III, Appendix 4, Section 5.2.4, and shall be calculated by the following equation:

where:

tp	=	physical response time, s
te	=	electrical response time, s

The calculations for estimating the filter cut-off frequency (fc) are based on a step input 0 to 1 in ≤ 0,01 s (see Annex VII). The response time is defined as the time between when the Bessel output reaches 10 % (t10) and when it reaches 90 % (t90) of this step function. This must be obtained by iterating on fc until t90-t10≈tF. The first iteration for fc is given by the following formula:

The Bessel constants E and K shall be calculated by the following equations:

where:

D	=	0,618034
Δt	=
Ω	=

6.1.2.   Calculation of the Bessel algorithm

Using the values of E and K, the 1 s Bessel averaged response to a step input Si shall be calculated as follows:

where:

Si-2	=	Si-1 = 0
Si	=	1
Yi-2	=	Yi-1 = 0

The times t10 and t90 shall be interpolated. The difference in time between t90 and t10 defines the response time tF for that value of fc. If this response time is not close enough to the required response time, iteration shall be continued until the actual response time is within 1 % of the required response as follows:

6.2.   Data evaluation

The smoke measurement values shall be sampled with a minimum rate of 20 Hz.

6.3.   Determination of smoke

6.3.1.   Data conversion

Since the basic measurement unit of all opacimeters is transmittance, the smoke values shall be converted from transmittance (τ) to the light absorption coefficient (k) as follows:

and

where:

k	=	light absorption coefficient, m-1
LA	=	effective optical path length, as submitted by instrument manufacturer, m
N	=	opacity, %
τ	=	transmittance, %

The conversion shall be applied, before any further data processing is made.

6.3.2.   Calculation of Bessel averaged smoke

The proper cut-off frequency fc is the one that produces the required filter response time tF. Once this frequency has been determined through the iterative process of Section 6.1.1, the proper Bessel algorithm constants E and K shall be calculated. The Bessel algorithm shall then be applied to the instantaneous smoke trace (k-value), as described in Section 6.1.2:

The Bessel algorithm is recursive in nature. Thus, it needs some initial input values of Si-1 and Si-2 and initial output values Yi-1 and Yi-2 to get the algorithm started. These may be assumed to be 0.

For each load step of the three speeds A, B and C, the maximum 1s value Ymax shall be selected from the individual Yi values of each smoke trace.

6.3.3.   Final result

The mean smoke values (SV) from each cycle (test speed) shall be calculated as follows:

For test speed A:	SVA = (Ymax1,A + Ymax2,A + Ymax3,A) / 3
For test speed B:	SVB = (Ymax1,B + Ymax2,B + Ymax3,B) / 3
For test speed C:	SVC = (Ymax1,C + Ymax2,C + Ymax3,C) / 3

where:

Ymax1, Ymax2, Ymax3

=

highest 1 s Bessel averaged smoke value at each of the three load steps

The final value shall be calculated as follows:

SV = (0,43 x SVA) + (0,56 x SVB) + (0,01 x SVC)

---

(1)  The test points shall be selected using approved statistical methods of randomisation.

(2)  The test points shall be selected using approved statistical methods of randomisation.

(3)  Based on C1 equivalent.

(4)  The value is only valid for the reference fuel specified in Annex IV.

Appendix 2

ETC TEST CYCLE

1.   ENGINE MAPPING PROCEDURE

1.1.   Determination of the mapping speed range

For generating the ETC on the test cell, the engine needs to be mapped prior to the test cycle for determining the speed vs torque curve. The minimum and maximum mapping speeds are defined as follows:

Minimum mapping speed	=	idle speed
Maximum mapping speed	=	nhi × 1,02 or speed where full load torque drops off to zero, whichever is lower

1.2.   Performing the engine power map

The engine shall be warmed up at maximum power in order to stabilise the engine parameters according to the recommendation of the manufacturer and good engineering practice. When the engine is stabilised, the engine map shall be performed as follows:

(a)	the engine shall be unloaded and operated at idle speed;

(b)	the engine shall be operated at full load setting of the injection pump at minimum mapping speed;

(c)	the engine speed shall be increased at an average rate of 8 ± 1 min-1 /s from minimum to maximum mapping speed. Engine speed and torque points shall be recorded at a sample rate of a least one point per second.

1.3.   Mapping curve generation

All data points recorded under Section 1.2 shall be connected using linear interpolation between points. The resulting torque curve is the mapping curve and shall be used to convert the normalised torque values of the engine cycle into actual torque values for the test cycle, as described in Section 2.

1.4.   Alternate mapping

If a manufacturer believes that the above mapping techniques are unsafe or unrepresentative for any given engine, alternate mapping techniques may be used. These alternate techniques must satisfy the intent of the specified mapping procedures to determine the maximum available torque at all engine speeds achieved during the test cycles. Deviations from the mapping techniques specified in this section for reasons of safety or representativeness shall be approved by the Technical Service along with the justification for their use. In no case, however, shall descending continual sweeps of engine speed be used for governed or turbocharged engines.

1.5.   Replicate tests

An engine need not be mapped before each and every test cycle. An engine shall be remapped prior to a test cycle if:

—	an unreasonable amount of time has transpired since the last map, as determined by engineering judgement, or

—	physical changes or recalibrations have been made to the engine which may potentially affect engine performance.

2.   GENERATION OF THE REFERENCE TEST CYCLE

The transient test cycle is described in Appendix 3 to this Annex. The normalised values for torque and speed shall be changed to the actual values, as follows, resulting in the reference cycle.

2.1.   Actual speed

The speed shall be unnormalised using the following equation:

The reference speed (nref) corresponds to the 100 % speed values specified in the engine dynamometer schedule of Appendix 3. It is defined as follows (see Figure 1 of Annex I):

where nhi and nlo are either specified according to Annex I, Section 2 or determined according to Annex III, Appendix 1, Section 1.1.

2.2.   Actual torque

The torque is normalised to the maximum torque at the respective speed. The torque values of the reference cycle shall be unnormalised, using the mapping curve determined according to Section 1.3, as follows:

Actual torque = (% torque × max. torque/100)

for the respective actual speed as determined in Section 2.1.

The negative torque values of the motoring points (‘m’) shall take on, for purposes of reference cycle generation, unnormalised values determined in either of the following ways:

—	negative 40 % of the positive torque available at the associated speed point,

—	mapping of the negative torque required to motor the engine from minimum to maximum mapping speed,

—	determination of the negative torque required to motor the engine at idle and reference speeds and linear interpolation between these two points.

2.3.   Example of the unnormalisation procedure

As an example, the following test point shall be unnormalised:

% speed	=	43
% torque	=	82

Given the following values:

reference speed	=	2 200 min-1
idle speed	=	600 min-1

results in,

actual speed = (43 × (2 200 - 600)/100) + 600 = 1 288 min-1

actual torque = (82 × 700/100) = 574 Nm

where the maximum torque observed from the mapping curve at 1 288 min-1 is 700 Nm.

3.   EMISSIONS TEST RUN

At the manufacturers request, a dummy test may be run for conditioning of the engine and exhaust system before the measurement cycle.

NG and LPG fuelled engines shall be run-in using the ETC test. The engine shall be run over a minimum of two ETC cycles and until the CO emission measured over one ETC cycle does not exceed by more than 10 % the CO emission measured over the previous ETC cycle.

3.1.   Preparation of the sampling filters (diesel engines only)

At least one hour before the test, each filter (pair) shall be placed in a closed, but unsealed Petri dish and placed in a weighing chamber for stabilisation. At the end of the stabilisation period, each filter (pair) shall be weighed and the tare weight shall be recorded. The filter (pair) shall then be stored in a closed Petri dish or sealed filter holder until needed for testing. If the filter (pair) is not used within eight hours of its removal from the weighing chamber, it must be conditioned and reweighed before use.

3.2.   Installation of the measuring equipment

The instrumentation and sample probes shall be installed as required. The tailpipe shall be connected to the full flow dilution system.

3.3.   Starting the dilution system and the engine

The dilution system and the engine shall be started and warmed up until all temperatures and pressures have stabilised at maximum power according to the recommendation of the manufacturer and good engineering practice.

3.4.   Starting the particulate sampling system (diesel engines only)

The particulate sampling system shall be started and running on by-pass. The particulate background level of the dilution air may be determined by passing dilution air through the particulate filters. If filtered dilution air is used, one measurement may be done prior to or after the test. If the dilution air is not filtered, measurements at the beginning and at the end of the cycle, may be done, and the values averaged.

3.5.   Adjustment of the full flow dilution system

The total diluted exhaust gas flow shall be set to eliminate water condensation in the system, and to obtain a maximum filter face temperature of 325 K (52 °C) or less (see Annex V, Section 2.3.1, DT).

3.6.   Checking the analysers

The emission analysers shall be set at zero and spanned. If sample bags are used, they shall be evacuated.

3.7.   Engine starting procedure

The stabilised engine shall be started according to the manufacturer's recommended starting procedure in the owner's manual, using either a production starter motor or the dynamometer. Optionally, the test may start directly from the engine preconditioning phase without shutting the engine off, when the engine has reached the idle speed.

3.8.   Test cycle

3.8.1.   Test sequence

The test sequence shall be started, if the engine has reached idle speed. The test shall be performed according to the reference cycle as set out in Section 2 of this Appendix. Engine speed and torque command set points shall be issued at 5 Hz (10 Hz recommended) or greater. Feedback engine speed and torque shall be recorded at least once every second during the test cycle, and the signals may be electronically filtered.

3.8.2.   Analyser response

At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the measuring equipment shall be started, simultaneously:

—	start collecting or analysing dilution air;

—	start collecting or analysing diluted exhaust gas;

—	start measuring the amount of diluted exhaust gas (CVS) and the required temperatures and pressures;

—	start recording the feedback data of speed and torque of the dynamometer.

HC and NOx shall be measured continuously in the dilution tunnel with a frequency of 2 Hz. The average concentrations shall be determined by integrating the analyser signals over the test cycle. The system response time shall be no greater than 20 s, and shall be coordinated with CVS flow fluctuations and sampling time/test cycle offsets, if necessary. CO, CO2, NMHC and CH4 shall be determined by integration or by analysing the concentrations in the sample bag, collected over the cycle. The concentrations of the gaseous pollutants in the dilution air shall be determined by integration or by collecting into the background bag. All other values shall be recorded with a minimum of one measurement per second (1 Hz).

3.8.3.   Particulate sampling (diesel engines only)

At the start of the engine or test sequence, if the cycle is started directly from the preconditioning, the particulate sampling system shall be switched from by-pass to collecting particulates.

If no flow compensation is used, the sample pump(s) shall be adjusted so that the flow rate through the particulate sample probe or transfer tube is maintained at a value within ± 5 % of the set flow rate. If flow compensation (i.e. proportional control of sample flow) is used, it must be demonstrated that the ratio of main tunnel flow to particulate sample flow does not change by more than ± 5 % of its set value (except for the first 10 seconds of sampling).

Note: For double dilution operation, sample flow is the net difference between the flow rate through the sample filters and the secondary dilution air flow rate.

The average temperature and pressure at the gas meter(s) or flow instrumentation inlet shall be recorded. If the set flow rate cannot be maintained over the complete cycle (within ± 5 %) because of high particulate loading on the filter, the test shall be voided. The test shall be rerun using a lower flow rate and/or a larger diameter filter.

3.8.4.   Engine stalling

If the engine stalls anywhere during the test cycle, the engine shall be preconditioned and restarted, and the test repeated. If a malfunction occurs in any of the required test equipment during the test cycle, the test shall be voided.

3.8.5.   Operations after test

At the completion of the test, the measurement of the diluted exhaust gas volume, the gas flow into the collecting bags and the particulate sample pump shall be stopped. For an integrating analyser system, sampling shall continue until system response times have elapsed.

The concentrations of the collecting bags, if used, shall be analysed as soon as possible and in any case not later than 20 minutes after the end of the test cycle.

After the emission test, a zero gas and the same span gas shall be used for re-checking the analysers. The test will be considered acceptable if the difference between the pre-test and post-test results is less than 2 % of the span gas value.

For diesel engines only, the particulate filters shall be returned to the weighing chamber no later than one hour after completion of the test and shall be conditioned in a closed, but unsealed Petri dish for at least one hour, but not more than 80 hours before weighing.

3.9.   Verification of the test run

3.9.1.   Data shift

To minimise the biasing effect of the time lag between the feedback and reference cycle values, the entire engine speed and torque feedback signal sequence may be advanced or delayed in time with respect to the reference speed and torque sequence. If the feedback signals are shifted, both speed and torque must be shifted the same amount in the same direction.

3.9.2.   Calculation of the cycle work

The actual cycle work Wact (kWh) shall be calculated using each pair of engine feedback speed and torque values recorded. This shall be done after any feedback data shift has occurred, if this option is selected. The actual cycle work Wact is used for comparison to the reference cycle work Wref and for calculating the brake specific emissions (see Sections 4.4 and 5.2). The same methodology shall be used for integrating both reference and actual engine power. If values are to be determined between adjacent reference or adjacent measured values, linear interpolation shall be used.

In integrating the reference and actual cycle work, all negative torque values shall be set equal to zero and included. If integration is performed at a frequency of less than 5 Hertz, and if, during a given time segment, the torque value changes from positive to negative or negative to positive, the negative portion shall be computed and set equal to zero. The positive portion shall be included in the integrated value.

Wact shall be between - 15 % and + 5 % of Wref

3.9.3.   Validation statistics of the test cycle

Linear regressions of the feedback values on the reference values shall be performed for speed, torque and power. This shall be done after any feedback data shift has occurred, if this option is selected. The method of least squares shall be used, with the best fit equation having the form:

where:

y	=	feedback (actual) value of speed (min-1), torque (Nm), or power (kW)
m	=	slope of the regression line
x	=	reference value of speed (min-1), torque (Nm), or power (kW)
b	=	y intercept of the regression line

The standard error of estimate (SE) of y on x and the coefficient of determination (r2) shall be calculated for each regression line.

It is recommended that this analysis be performed at 1 Hertz. All negative reference torque values and the associated feedback values shall be deleted from the calculation of cycle torque and power validation statistics. For a test to be considered valid, the criteria of Table 6 must be met.

Table 6

Regression line tolerances

	Speed	Torque	Power
Standard error of estimate (SE) of Y on X	Max 100 min–1	Max 13 % (15 %) (1) of power map maximum engine torque	Max 8 % (15 %) (1) of power map maximum engine power
Slope of the regression line, m	0,95 to 1,03	0,83–1,03	0,89–1,03 (0,83–1,03) (1)
Coefficient of determination, r2	min 0,9700 (min 0,9500) (1)	min 0,8800 (min 0,7500) (1)	min 0,9100 (min 0,7500) (1)
Y intercept of the regression line, b	± 50 min-1	± 20 Nm or ± 2 % (± 20 Nm or ± 3 %) (1) of max torque whichever is greater	± 4 kW or ± 2 % (± 4 kW or ± 3 %) (1) of max power whichever is greater

Point deletions from the regression analyses are permitted where noted in Table 7.

Table 7

Permitted point deletions from regression analysis

Conditions	Points to be deleted
Full load and torque feedback < torque reference	Torque and/or power
No load, not an idle point, and torque feedback > torque reference	Torque and/or power
No load/closed throttle, idle point and speed > reference idle speed	Speed and/or power

4.   CALCULATION OF THE GASEOUS EMISSIONS

4.1.   Determination of the diluted exhaust gas flow

The total diluted exhaust gas flow over the cycle (kg/test) shall be calculated from the measurement values over the cycle and the corresponding calibration data of the flow measurement device (V0 for PDP or KV for CFV, as determined in Annex III, Appendix 5, Section 2). The following formulae shall be applied, if the temperature of the diluted exhaust is kept constant over the cycle by using a heat exchanger (± 6 K for a PDP-CVS, ± 11 K for a CFV-CVS, see Annex V, Section 2.3).

For the PDP-CVS system:

MTOTW = 1,293 × V0 × Np × (pB – p1) × 273 / (101,3 × T)

where:

MTOTW	=	mass of the diluted exhaust gas on wet basis over the cycle, kg
V0	=	volume of gas pumped per revolution under test conditions, m3/rev
NP	=	total revolutions of pump per test
pB	=	atmospheric pressure in the test cell, kPa
p1	=	pressure depression below atmospheric at pump inlet, kPa
T	=	average temperature of the diluted exhaust gas at pump inlet over the cycle, K

For the CFV-CVS system:

MTOTW = 1,293 × t × Kv × pA / T0,5

where:

MTOTW	=	mass of the diluted exhaust gas on wet basis over the cycle, kg
t	=	cycle time, s
Kv	=	calibration coefficient of the critical flow venturi for standard conditions
pA	=	absolute pressure at venturi inlet, kPa
T	=	absolute temperature at venturi inlet, K

If a system with flow compensation is used (i.e. without heat exchanger), the instantaneous mass emissions shall be calculated and integrated over the cycle. In this case, the instantaneous mass of the diluted exhaust gas shall be calculated as follows:

For the PDP-CVS system:

MTOTW,i = 1,293 × V0 × Np,i × (pB – p1) × 273 / (101,3 × T)

where:

MTOTW,i	=	instantaneous mass of the diluted exhaust gas on wet basis, kg
Np,i	=	total revolutions of pump per time interval

For the CFV-CVS system:

MTOTW,i = 1,293 × Δti × Kv × pA / T0,5

where:

MTOTW,i	=	instantaneous mass of the diluted exhaust gas on wet basis, kg
Δti	=	time interval, s

If the total sample mass of particulates (MSAM) and gaseous pollutants exceeds 0,5 % of the total CVS flow (MTOTW), the CVS flow shall be corrected for MSAM or the particulate sample flow shall be returned to the CVS prior to the flow measuring device (PDP or CFV).

4.2.   NOx correction for humidity

As the NOx emission depends on ambient air conditions, the NOx concentration shall be corrected for ambient air humidity with the factors given in the following formulae:

(a)	for diesel engines:

(b)	for gas engines:

where:

Ha

=

humidity of the intake air water per kg dry air

in which:

Ra	=	relative humidity of the intake air, %
pa	=	saturation vapour pressure of the intake air, kPa
pB	=	total barometric pressure, kPa

4.3.   Calculation of the emission mass flow

4.3.1.   Systems with constant mass flow

For systems with heat exchanger, the mass of the pollutants (g/test) shall be determined from the following equations:

where:

NOx conc, COconc, HCconc  (2), NMHCconc

=

average background corrected concentrations over the cycle from integration (mandatory for NOx and HC) or bag measurement, ppm

MTOTW	=	total mass of diluted exhaust gas over the cycle as determined in Section 4.1, kg
KH,D	=	humidity correction factor for diesel engines as determined in Section 4.2
KH,G	=	humidity correction factor for gas engines as determined in Section 4.2

Concentrations measured on a dry basis shall be converted to a wet basis in accordance with Annex III, Appendix 1, Section 4.2.

The determination of NMHCconc depends on the method used (see Annex III, Appendix 4, Section 3.3.4). In both cases, the CH4 concentration shall be determined and subtracted from the HC concentration as follows:

(a)

GC method

(b)	NMC method

where:

HC(wCutter)	=	HC concentration with the sample gas flowing through the NMC
HC(w/oCutter)	=	HC concentration with the sample gas bypassing the NMC
CEM	=	methane efficiency as determined per Annex III, Appendix 5, Section 1.8.4.1
CEE	=	ethane efficiency as determined per Annex III, Appendix 5, Section 1.8.4.2

4.3.1.1.   Determination of the background corrected concentrations

The average background concentration of the gaseous pollutants in the dilution air shall be subtracted from measured concentrations to get the net concentrations of the pollutants. The average values of the background concentrations can be determined by the sample bag method or by continuous measurement with integration. The following formula shall be used.

where:

conc	=	concentration of the respective pollutant in the diluted exhaust gas, corrected by the amount of the respective pollutant contained in the dilution air, ppm
conce	=	concentration of the respective pollutant measured in the diluted exhaust gas, ppm
concd	=	concentration of the respective pollutant measured in the dilution air, ppm
DF	=	dilution factor

The dilution factor shall be calculated as follows:

(a)	for diesel and LPG fuelled gas engines

(b)	for NG-fuelled gas engines

where:

CO2, conce	=	concentration of CO2 in the diluted exhaust gas, % vol
HCconce	=	concentration of HC in the diluted exhaust gas, ppm C1
NMHCconce	=	concentration of NMHC in the diluted exhaust gas, ppm C1
COconce	=	concentration of CO in the diluted exhaust gas, ppm
FS	=	stoichiometric factor

Concentrations measured on dry basis shall be converted to a wet basis in accordance with Annex III, Appendix 1, Section 4.2.

The stoichiometric factor shall be calculated as follows:

where:

x, y

=

fuel composition CxHy

Alternatively, if the fuel composition is not known, the following stoichiometric factors may be used:

FS (diesel)	=	13,4
FS (LPG)	=	11,6
FS (NG)	=	9,5

4.3.2.   Systems with flow compensation

For systems without heat exchanger, the mass of the pollutants (g/test) shall be determined by calculating the instantaneous mass emissions and integrating the instantaneous values over the cycle. Also, the background correction shall be applied directly to the instantaneous concentration value. The following formulae shall be applied:

where:

conce	=	concentration of the respective pollutant measured in the diluted exhaust gas, ppm
concd	=	concentration of the respective pollutant measured in the dilution air, ppm
MTOTW,i	=	instantaneous mass of the diluted exhaust gas (see Section 4.1), kg
MTOTW	=	total mass of diluted exhaust gas over the cycle (see Section 4.1), kg
KH,D	=	humidity correction factor for diesel engines as determined in Section 4.2
KH,G	=	humidity correction factor for gas engines as determined in Section 4.2
DF	=	dilution factor as determined in Section 4.3.1.1

4.4.   Calculation of the specific emissions

The emissions (g/kWh) shall be calculated for all individual components in the following way:

(diesel and gas engines)

(diesel and gas engines)

(diesel and LPG fuelled gas engines)

(NG fuelled gas engines)

(NG fuelled gas engines)

where:

Wact

=

actual cycle work as determined in Section 3.9.2, kWh

5.   CALCULATION OF THE PARTICULATE EMISSION (DIESEL ENGINES ONLY)

5.1.   Calculation of the mass flow

The particulate mass (g/test) shall be calculated as follows:

where:

Mf	=	particulate mass sampled over the cycle, mg
MTOTW	=	total mass of diluted exhaust gas over the cycle as determined in Section 4.1, kg
MSAM	=	mass of diluted exhaust gas taken from the dilution tunnel for collecting particulates, kg

and:

Mf	=	Mf,p + Mf,b if weighed separately, mg
Mf,p	=	particulate mass collected on the primary filter, mg
Mf,b	=	particulate mass collected on the back-up filter, mg

If a double dilution system is used, the mass of the secondary dilution air shall be subtracted from the total mass of the double diluted exhaust gas sampled through the particulate filters

where:

MTOT	=	mass of double diluted exhaust gas through particulate filter, kg
MSEC	=	mass of secondary dilution air, kg

If the particulate background level of the dilution air is determined in accordance with Section 3.4, the particulate mass may be background corrected. In this case, the particulate mass (g/test) shall be calculated as follows:

where:

Mf, MSAM, MTOTW

=

see above

MDIL	=	mass of primary dilution air sampled by background particulate sampler, kg
Md	=	mass of the collected background particulates of the primary dilution air, mg
DF	=	dilution factor as determined in Section 4.3.1.1

5.2.   Calculation of the specific emission

The particulate emission (g/kWh) shall be calculated in the following way:

where:

Wact

=

actual cycle work as determined in Section 3.9.2, kWh.

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(1)  Until 1 October 2005, the figures shown in brackets may be used for the type-approval testing of gas engines. The Commission shall report on the development of gas engine technology to confirm or modify the regression line tolerances applicable to gas engines given in this table.

(2)  Based on C1 equivalent.