The Ministry of industry and trade
of 6 May 1999. September 2000,
laying down the requirements for water meters for cold water called
Change: 260/2003 Coll.
The Ministry of industry and trade shall determine in accordance with section 27 of Act No. 506/1990
Coll. on metrology, as amended by Act No. 121/2000 Coll. (hereinafter the "Act")
for the implementation of § 6 (1). 2 and § 9 para. 1 of the Act:
This Decree lays down the requirements for water meters for cold potable water (hereinafter referred to as
"meters"). For the purpose of this order is deemed to be cold water
If the temperature in the range from 0 ° C to 30 ° c.
Water meters can be instead of marking the official marks laid down
special legal regulation ^ 1) marked by an EEC type-approval, and
the initial EEC verification, whose graphic design provides for a specific legal
prescription, ^ 2) only if they meet the requirements set out in the annex to this
the Decree, and that it was verified the procedures laid down in a special
legislation. ^ 2)
This Decree shall take effect on the date of publication of the sectoral annex for
the measuring instrument to the Protocol to the Europe Agreement establishing an association between the
The Czech Republic on the one hand, and the European communities and their
Member States, of the other part, on conformity assessment and acceptance of
industrial products in the collection of international treaties, or on the date of entry
the Treaty of accession of the Czech Republic to the European Union entered into force,
If the day earlier.
doc. Ing. Gregr, r.
The meters requirements
TERMINOLOGY AND DEFINITIONS
This annex applies only to cold-water meters based on direct mechanical
the principle, which is based on the use of volumetric Chambers with moving
walls or on the influence of the velocity of the water on the speed of rotation of the moving
(radial or axial turbine).
Flow is the volume of water passing through the meter per unit of time and
This volume is expressed in cubic metres or litres and the time in
hours, minutes, or seconds.
1.2 volume delivered
Volume delivered is the total volume of water that has passed through the meter for a given
period of time.
1.3 Maximum flowrate (Qmax)
Maximum flowrate, Qmax, is the highest flowrate at which the meter can
function over limited periods without damage, and without exceeding the
the maximum permissible errors and the maximum permissible value for loss of pressure.
1.4. Nominal flowrate (Qn)
Nominal flow Qn, is equal to half the maximum flowrate, Qmax. This
the flow rate is expressed in cubic metres per hour and is used for
indication of the meter.
At the nominal flowrate, Qn, the meter must be able to function in normal
use, i.e.,. for continuous and intermittent operating conditions, without
you have exceeded the maximum permissible errors.
1.5 the minimum flowrate (Qmin)
The minimum flow Qmin is the flowrate above which the value of the meter shall not
exceed the maximum permissible errors and that is fixed as
a function of qn.
1.6. Flowrate range
The flowrate range of the meter is bounded by the maximum and minimum flowrates,
Qmax and Qmin. This range is divided into two regions, known as
the top and bottom, with different maximum permissible errors.
1.7. Transitional flowrate (Qt)
The transitional flowrate, Qt, is the flowrate which divides the upper and lower range
the flow and in which regions the maximum permissible error.
1.8. Maximum permissible error
The maximum permissible error is the error of the meter allowed for
EEC type-approval and the initial EEC verification pursuant to this order.
1.9. Pressure loss
Loss of pressure means the loss which is caused by the presence of a water meter
in the pipeline.
2.1. Maximum permissible errors
The maximum error permitted in the lower range from Qmin inclusive to Qt
(except) is +/-5%.
The maximum permissible error in the upper region from Qt inclusive to Qmax
(including) is +/-2%.
2.2. Metrological classes
Water meters are divided, according to the above values of Qmin and Qt defined into three
metrological classes in the following table:
| Class | Qn |
| | < 15 m3/h | > = 15 m3/h |
| Class A | | |
| Value: Qmin | 0.04 Qn | 0.08 Qn |
| Value: Qt | 0.10 Qn | 0.30 Qn |
| Class B | | |
| Value: Qmin | 0.02 Qn | 0.03 Qn |
| Value: Qt | 0.08 Qn | 0.20 Qn |
| Class C | | |
| Value: Qmin | 0.01 Qn | 0.006 Qn |
| Value: Qt | 0.015 Qn | 0.015 Qn |
3.1 Construction-General provisions
The meter must be constructed in such a way as to:
(a) give long service and guarantee proof against fraud
(b) under normal conditions of use, conform with the provisions of this Ordinance.
Where meters may be subjected to an accidental reversal of flow,
must be able to change this without damage, and without changing their
metrological properties, and at the same time it must reverse the flow
The meter must be made of materials of adequate strength and stability, which
correspond to the purpose for which it will be used. The meter must be completely
made of materials that are resistant to internal and normal external
corrosion, and, if necessary, must be equipped with a suitable surface treatment.
Water temperature variations within the working temperature range must not adversely
affect the materials used for the manufacture of the meter.
3.3. pressure tightness-proofness
The meter must be able to indefinitely, while maintaining the correct
function, no leaks, leaking walls and permanent deformation
to withstand the constant pressure of water, for which it is designed, and which is called the
the maximum operating pressure. The minimum value for this pressure is 1000 kPa (10
3.4 pressure loss
Pressure drop across the meter is determined during the tests for the EEC
type-approval, and shall not exceed 25 kPa (0.25 bar) at nominal
the flow and 100 kPa (1 bar) at the maximum flowrate.
Based on the results of tests with water meters shall be placed into one of four groups
with the following maximum values for pressure loss: 100; 60; 30, and 10
kPa (1.0; 0.6; 0.3 and 0.1 bar). The appropriate value must be indicated in the
EEC type-approval certificate.
3.5 the indicating device
The indicating device must make it through a simple and
juxtaposition of its various parts, reliable, easy and
unambiguous reading of the volume of water measured, expressed in meters
cubic. This volume is given one of the following options:
and) by the position of one or more pointers on circular scales,
(b)) by displaying a series of consecutive digits in one or more apertures,
(c)) the combination of these two systems.
The cubic metre and its multiples must be displayed with black paint, parts
cubic meter must be displayed in red.
Optical height of the figures must not be less than 4 mm.
On digital indicators type b), and (c)) visible displacement of all must be
numbers vertically upwards. The offset of any numerical units must be
completed at the time when the next lower decade changes from 9 to
0; the roller showing the least significant digits, type c)
move continuously. Complete the number of cubic metres must be clearly
Indicators with pointers of type a) and (c)) must rotate in the direction of
clockwise. The value of each Division of the scale in metres
cubic 10En must be expressed as, where n is a positive or negative
whole number or zero, thereby establishing a system of consecutive decades. In
near each part of the scale shall bear the following markings:
x 1000 x 100 x 10 x 1 x x 0.1 0.01 x 0.001.
In both cases (dial and digital indicators):
-the unit symbol m3 must be shown either on the dial or in the
the immediate vicinity of the digital indication,
-the fastest-spinning and visually readable graduated element (
"the control element") must move continuously; his piece is known as
verification scale interval. Control element may be permanent or may be
created temporarily by adding detachable parts. These parts must not have
a significant influence on the metrological characteristics of the meter.
The length of the verification scale interval shall not be less than 1 mm and not
greater than 5 mm. Scale must contain:
and tags) of the same width, which is not more than one quarter of the
the distance between the axes of two adjacent marks that differ only in their
(b)) of contrasting bands of a constant width equal to the length of one of the interval
3.6 number of digits and the value of the verification scale interval
The indicating device must be able to record without returning to zero
the volume in cubic meters, which is equivalent to at least 1 999
hours of operation at the nominal flow rate.
The value of the verification scale interval must be 1 x 10En or
2 x or 5 x 10En 10En. When the value of the authentication must be sufficiently
small, in order to ensure that the measurement inaccuracy of not more than 0.5% (as of
consideration is allowing for a possible reading error of not more than half the length of the
the smallest scale interval) and that at the minimum flowrate did not last
test more than 1 1/2 hours.
It is possible to add a supplementary device (Star, disc with a reference
mark, etc.), in order to show the movement of the measuring instrument before
It will be clearly visible on the indicating device.
3.7 adjustment device
The meter may be equipped with an adjustment device with which it is possible to
to change the ratio between the volume indicated and the volume actually
passed. This device is compulsory for meters which make use
the action of the velocity of the water on the rotation of the moving parts.
3.8. Accelerating device
Use of an accelerating device for increasing the speed of the meter when you
flow rates below Qmin is prohibited.
MARKS AND INSCRIPTIONS
4.1 Identification inscriptions
For all water meters is required to bear in legible and indelible
the form of the following information, either separately or grouped together on the
the meter casing, the indicator on the dial or on the information plate:
and the name of the manufacturer) or business name or the trade mark,
(b)) the metrological class and nominal flowrate Qn in m3/h,
c) year of manufacture and the serial number,
(d)) one or two arrows showing the direction of flow,
(e)) EEC type-approval mark,
(f)) the maximum operating pressure in bar, if greater than 1 000 kPa (10
(g)) the letter "V" or "H" If the meter can operate properly only
in the vertical (V) or horizontal (H) position.
4.2 location of the initial EEC verification marks
To affix the EEC verification mark must be the essential part (normally
on the meter casing) instead, which is visible without disassembly
the water meter.
The meter must be equipped with means of protection to seal
in such a way as to ensure that the correct before installing the meter
and the meter will not be possible for her or its adjustment device without damage
protective equipment to remove or change.
EEC type-approval shall be carried out under a special legal
prescription ^ 2).
When it has been ascertained from the application file that the pattern conforms to the
the provisions of this Ordinance, then the laboratory tests must be carried out on
a number of instruments under the following conditions:
5.2.1 number of meters to be tested
Number of meters to be submitted by the manufacturer is as shown in the following
| Nominal flow Qn, m3/h | The number of water meters |
| Qn 10 | | | | | | |
| | 2 Qn | continuous | | | 200 h | |
(*) (Qn) is a number equal to the value of Qn, expressed in m3/h.
Before the first test and after each series of tests shall determine the error
measurement; the minimum requirement is to be determined at the following
the following flow rates:
Qmin, Qt Qn 0.5 0.3 Qn 1 Qn 2 Qn
During each test, the volume of water must be flowing through the meter
large enough to turn the pointer or roller on the verification
the scale of one or more complete revolutions and to eliminate the effects of
5.2.5. Conditions for EEC type-approval
Type of meter is approved if it meets the following conditions:
a) corresponds to the administrative, technical and metrological provisions of this
the Ordinance and its annex,
b) tests and), b) and (c)) under point 5.2.4 show that matches in terms of
metrological and technological characteristics of parts II and III of this
of the annex,
c) after each accelerated endurance test:
1. no change was observed in relation to the initial curve greater than
1.5% between Qt and Qmax or greater than 3% between Qmin and Qt,
2. the maximum error of the meter between Qmin and Qt is +/-6% between Qt and Qmax
THE INITIAL EEC VERIFICATION
This verification shall be carried out in a place approved by the Czech metrology
Institute. Layout of the premises and equipment must be such that the
verification may be carried out in safe, reliable conditions and without
loss of time for the persons who are responsible for these tests. Must be
comply with the provisions of point 5.2.3, but if it is desirable,
water meters to be tested in series. If this method is used, then the output
the pressure of all the meters must be sufficient; in order to avoid cavitation,
Special measures may be taken to prevent interference
The complete unit may include automatic devices, by-pass
valves, flow limiters, etc. assuming that each test circuit
among the verified meters and control tanks is clearly defined and
that is possible at any time to check the internal pressure tightness of these
You can use any type of water supply system, but if
several test circuits are operated in parallel, then between them
There are no interference incompatible with the provisions of section
If a control tank is divided into several chambers, the separating
the walls must be sufficiently rigid to ensure that the volume of any
the Chamber does not vary by more than ± 0.2% according to whether the adjacent
Chambers are full or empty.
Verification of the accuracy test at least includes three
the following flow rates:
and) between 0.9 Qmax and Qmax,
(b)) between Qt and Qt, 1.1
c) between Qmin and 1.1 Qmin.
The first of these tests involves the determination of pressure losses, which should
be less than the value indicated in the EEC pattern approval certificate.
The maximum permissible errors are specified in section 2.1.
In each test, the quantity of water must be flowing through the meter is sufficiently
big, to turn a pointer or roller on the verification scale through one
or more complete revolutions and to limit the effects of cyclic distortion.
If it is found that all the errors lie in one direction, then the water meter
You must set up so that all errors do not exceed half of the maximum
1) Decree No. 262/2000 Coll., which ensures consistency and accuracy
measuring instruments and measurements.
2) Decree No. 332/2000 Coll., laying down some of the procedures in the
type-approval and verification of measuring instruments, called marker set