Č e s k ý  m e t r o l o g i c k ý  i n s t i t u t  
Okružní 31,  638 00  
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1. ------IND- 2014 0079 CZ - EN- ------ 20140227 --- --- PROJET  
Executive summary for the EC   (is not part of this legislation)  
Technical and metrological requirements specified in the MGA are based on and identical to 
corresponding requirements of standard s ČSN EN ISO 5167 -1 and ČSN EN ISO 5167 -2, which are 
globally agreed -upon optimum solutions for the calculation, design and manufacture of “orifice 
plates”.  
(End of executive summary)  
 
 
 
 
 
The Czech Metrology Institute (CMI), as the competent local body f or stipulating metrological and 
technical requirements for a specified measuring instrument and for the stipulation of test methods for 
type approval and for verification of a specified measuring instrument pursuant to § 14(1) of Act No. 
505/1990, on metro logy, as amended (hereinafter the “Metrology Act”), and pursuant to provisions of 
§ 172 et seq. of Act No. 500/2004, the Administrative Code, as amended (hereinafter the “AC”), has 
on 22 November 2013 commenced ex officio proceedings pursuant to § 46 of th e AC, and based on 
supporting documents issues this:  
 
 
I. 
MEASURE OF A GENERAL  NATURE  
number:  0111 -OOP -C041-13 
reference no . 0313/0 12/13/Pos., 
 
stipulating metrological and technical requirements for specified measuring instruments, 
including test methods for type approval and verification of specified measuring instruments:  
 “diaphragm sensors for measuring transmission media flow”  
 Measure of a General Nature No. 0111 -OOP -C041 -13 
2 1   Basic definitions  
For the purposes of this measure of a general nature, terminology and definitions contained in  VIM 
and VIML1) and the following terminology and definitions apply:  
1.1 
transmission medium   
a liquid used to transmit heat; for purposes of this measure of a general nature, this means water 
vapour, i.e. the gaseous phase of water and/or condensate  
1.2 
measuring system for measuring transmission medium flow   
a system consisting of one or more measuring instruments (measuring instrument elements) and often 
other devices, assembled and adapted for providing information regarding the qualitative and 
quantitative char acteristics of a transmission medium  
1.3 
diaphragm sensor for measuring transmission medium flow   
a transmission medium flow sensor based on the principle of measuring the pressure differential 
between the front and rear of a diaphragm plate with a central  diaphragm inserted in a defined manner 
in pipes with specified geometric parameters  
1.4 
diaphragm plate   
a thin plate containing a circular opening – a diaphragm  
1.4.1 
front side  A  
the side of the diaphragm plate installed in the direction of gas inflow,  with higher quality 
requirements  
1.4.2 
rear side  B  
the side of the diaphragm plate installed in the direction of gas outflow, with lower quality 
requirements and an area for marking  
1.5 
diaphragm   
a concentric circular opening in a diaphragm plate  
1.6 
pressure sampling (in wall)   
an annular or circular opening drilled into the wall of a pipe so that the edge of the opening is flush 
with the inside surface of the pipe  
NOTE: Diaphragms may be used with corner pressure sampling and with flange pressure sampl ing, or with 
pressure sampling at distances D and D/2. 
1.7 
static pressure of a transmission medium flowing through a pipe   
pressure that can be measured by connecting a pressure meter in the wall  
                                                   
1)  The International Vocabulary of Metrology - Basic and General Concepts and Associated Terms (VIM) and 
the International Vocabulary of Terms in Legal Metrology (VIML) are part of the “Terminolo gy in the Area of 
Metrology”  technical harmonisation compendium  that is publicly available at www.unmz.cz  Opatření obecné povahy č. 0111 -OOP -C041-13 
3 1.8  
differential pressure    
the difference between (static ) pressures measured in pressure sampling locations in the wall, one 
being in front of and the other behind a diaphragm plate inserted into a straight section pipe through 
which the transmission medium is flowing, taking into account all differences in sam pling height in 
front of and behind the diaphragm plate  
1.9 
diameter ratio  β  
the ratio of the diameter of the opening in the diaphragm plate to the inside diameter of the pipe in 
front of the diaphragm plate  
1.10 
pipe Reynolds number  ReD   
a dimensionless  parameter expressing the ratio of inertial forces to friction forces in the pipe in front 
of the diaphragm plate  
1.11 
flow rate coefficient C  
a coefficient defined for a stream of incompressible liquid; it gives the ration of the true flow rate 
through a  diaphragm to the theoretical flow rate  
1.12 
expansion coefficient   
a coefficient characterising the degree of compressibility of the liquid under consideration  
2    Metrological requirements  
The specified metrological requirements are comparable to releva nt requirements of European 
standards and area applied to basic versions of diaphragm sensors for measuring transmission media 
flow.  
During verification, diaphragm sensors for measuring transmission media flow  are subject to 
metrological requirements that were applicable for their being placed into circulation.  
2.1.   Service conditions  
Service conditions are specified the manufacturer, taking into account the range of expected ambient 
temperatures during operation and the temperature range of the transmiss ion medium. In the case of 
significant temperature differences between the ambient temperature and the temperature of the flowing 
transmission medium, the flow sensor must be thermally insulated in a suitable manner.  
For diaphragm sensors for measuring tra nsmission media flow, the following conditions apply for 
individual sampling methods:  
– with corner pressure sampling : for 0.10 ≤ β ≤ 0,56 :  ReD ≥ 5000  
  for β > 0.56 : ReD ≥ 16,000 β2 
– with flange pressure sampling : ReD ≥ 5000 a nd ReD ≥ 170 β2 D, where  D is in mm 
– with sampling at distances  D and D/2: for 0.10 ≤ β ≤ 0,56 :  ReD ≥ 5000 
  for β > 0.56 : ReD ≥ 16,000 β2 
2.2   Usage l imits  
Diaphragm sensors for measuring transmission media flow may be used only for:  
– pipes with an internal diameter  D: 50 mm to 1 000 mm Measure of a General Nature No. 0111 -OOP -C041 -13 
4 – minimum diaphragm diameter  d: 12.5 mm 
– diameter ratio  β (d/D):  0.1 to 0.75 
2.3    Relative uncertainty  of the diaphragm flow rate coefficient  
When all technical requirements and installation requirements are met within limits that do not require 
an increase in the relative uncertainty of the flow  rate coefficient by additional uncertainties, the 
following relative uncertain ties of the flow  rate coefficient C apply for diaphragms:  
(0.7 – β) %  for 0.1 ≤ β < 0.2 
0.5 %  for 0.2 ≤ β ≤ 0.6 
(1.667β – 0.5) %  for 0.6 < β ≤ 0.75 
If D < 71.12 mm, a relative uncertainty of 0.9 (0.75 – β) (2.8 – D/25.4) % must be added to the above 
relative uncertainty values for the flow rate, where D is in millimet res. 
If β > 0.5 and ReD < 10 000, a relative uncertainty of 0.5 % must be added to the above relative 
uncertainty values for the flow rate.  
If straight sections of pipe with a n additional uncertainty are used, this uncertainty must be added to 
the flow rat e coefficient uncertainty. The use of a straight section of pipe with additional uncertainty is 
restricted only to the section in front of the diaphragm plate, or only to the section behind the 
diaphragm plate.  
Fulfilment of technical requirements is deter mined during verification of individual parts of a 
diaphragm sensor for measuring transmission media flow.  
2.4    Relative uncertainty of the expansion coefficient  
When all specified technical requirements are met, the relative uncertainty of the expansion  coefficient 
ε is 3.5
1pκp %, where κ is the isentropic exponent, Δ p the differential pressure and p1 the absolute 
static pressure of the transmission medium in front of the diaphragm plate.  
Fulfilment of technical requirements is determine d during verification of individual parts of the 
transmission medium flow rate sensor.  
3    Technical requirements  
The specified technical requirements are comparable to relevant requirements of European standards 
and area applied to basic versions of diaphragm sensors for measuring transmission media flow.  
During verification, measuring instruments are subject to technical requirements that were applicable 
for their being placed into circulation.  
3.1   Design  
The basic version of a diaphragm sensors for me asuring transmission media flow includes the 
following parts:  
– a diaphragm plate with a diaphragm;  
– pressure sampling;  
– a calming straight section of pipe in front of the diaphragm plate with a total length of 10 D, or 
if installation requirements for the meas uring system permit, a shorter section;  
– a calming straight section of pipe past the diaphragm plate of length 2 D. Opatření obecné povahy č. 0111 -OOP -C041-13 
5 The design and installation of the diaphragm plate must ensure that it does not undergo plastic or 
elastic deformation under the pressure of t he transmission medium, or for this deformation to be 
within specified limits.  
3.2    Diaphragm plate  
The part of the diaphragm plate of diameter D that is located inside the pipe after installation must be 
circular and concentric with the pipe axis. The f ront and back of the diaphragm must be parallel.  
Unless specified otherwise, all design and manufacturing requirements for the diaphragm plate apply 
only to that portion that is located inside the pipe.  
3.2.1    Front side A  
3.2.1.1    Flatness  
The maximum deviation between a straight ruler of length D, placed in an arbitrary direction above a 
diameter D on the diaphragm plate and the plane of the front side of the diaphragm plate A, must be 
less than 0.005( D – d)/2, i.e. the surface angle must be less than 0.5 %.  
3.2.1.2    Surface roughness  
Inside a circle of diameter D, concentric with the diaphragm opening d, the diaphragm plate must have 
a roughness parameter of Ra < 10-4 d. 
3.2.2    Rear side B 
The rear side of the diaphragm plate must be flat and paralle l to the front side. The surface roughness 
on the rear side of the diaphragm plate need not achieve the quality required for the front side of the 
diaphragm plate.  
3.2.3     Thickness of the diaphragm opening  e and thickness of the diaphragm plate  E 
The thi ckness of the diaphragm opening e must be between 0.005 D and 0.02 D. The difference 
between values of e measured at an arbitrary point in the diaphragm opening must not be greater than 
0.001 D. 
The thickness of the diaphragm plate E must be between e and 0.0 5D. If 50  mm ≤ D ≤ 64 mm, a value 
of E up to 3.2 mm is permitted.  
The difference between values of E measured at an arbitrary point for diaphragm plates with 
D ≥ 200 mm must not be greater than 0.001 D. For diaphragm plates with D < 200 mm, the difference 
between values of E measured at an arbitrary point must not be greater than 0.2 mm.  
3.2.4    Bevel angle  α 
If the thickness E of the diaphragm plate is greater than the thickness of the diaphragm opening e, the 
diaphragm opening on the rear side of the diaph ragm plate must be bevelled; the bevel angle α must be 
45° ± 15°. The bevelled surface must be smooth.  
3.2.5    Edges of the diaphragm opening  
The front edge of the diaphragm opening must not have any barbs or other damage. The edge must be 
sharp and right -angled. The radius of curvature of the front edge of the diaphragm opening must not be 
greater than 0.0004 d. 
The angle between the diaphragm opening and the front side of the diaphragm plate must be 
90° ± 0,3°. 
The rear edge or edges of the diaphragm openi ng need not meet quality requirements for the front 
edge of the diaphragm opening.  Measure of a General Nature No. 0111 -OOP -C041 -13 
6 3.2.6     Diaphragm opening diameter  d 
The diaphragm opening diameter d must meet requirements listed in article  2.2. 
The size of the diaphragm opening diameter d is the mean  value obtained from the measurement of at 
least four diameters approximately the same angle relative to each other.  
3.2.7     Cylindric ity of the diaphragm opening  
The diaphragm opening must be cylindrical; no diameter measured in the cylindrical part of t he 
diaphragm opening may differ by more than 0.05 % from the mean value of the diameter d. 
3.2.8     Diaphragm opening surface roughness  
The surface roughness of the cylindrical part of the diaphragm opening must not affect edge sharpness 
measurement.  
3.2.9     Diaphragm plate material  
The diaphragm plate may be manufactured from any material with a known longitudinal coefficient of 
expansion, under the assumption that it shall continue to meet all relevant requirements of this 
legislation under service condi tions.  
3.2.10     Diaphragm plate design for bi -directional flow  
For diaphragm plates intended for measuring transmission medium flow rate in both directions, the 
technical and metrological requirements for front side A of the diaphragm plate must be applie d to 
both sides of the diaphragm plate (edge).  
3.3    Differential pressure sampling  
Flange pressure sampling, corner pressure sampling or pressure sampling at distances D and D/2 may 
be used to sample differential pressure.  
If transmission medium diaphrag m sensor is of bi -directional design and pressure is sampled at distances 
D and D/2, two sampling pair must be used in front of and behind the diaphragm according to flow 
direction.  
3.4    Straight sections of pipe in front of and behind the diaphragm plat e 
3.4.1    Design  
The minimum straight length of pipe in front of the diaphragm plate that must be adhered to in a 
specific application is determined using the diameter ratio β and according to the type and mutual 
arrangement of at least two pipe fittings l ocated in front of the diaphragm plate.  
The straight section of pipe between the first pipe fitting in front of the diaphragm plate and the 
diaphragm plate itself may be composed of one or more pieces. The section of pipe up to a length of 
2D in front of t he diaphragm plate must always consist of one piece.  
The design and manufacture of straight pipe sections must allow the performance of tests defined in 
article 5.2.4 or article 6.2.4, as the case may be.  
3.4.2    Pipe straightness  
The straightness of calm ing minimum straight sections of pipe is considered sufficient if the surface of 
the pipe s does not deviate from a straight line parallel to the pipe axis by more than 0.4 % of their 
length in front of and behind the diaphragm plate.  Opatření obecné povahy č. 0111 -OOP -C041-13 
7 3.4.3    Mean internal  pipe diameter  value  
The mean value of the internal pipe diameter D is the arithmetic average of at least twelve measured 
diameter values , i.e. four diameters at approximately the same angles from each other in each of at 
least three cross -sections equally  dispersed over a length of 0.5 D in front of the diaphragm plate. Two 
of these cross -sections must be located in the  plane of the  front pressure sampling point  and at a 
distance of 0.5D from the front pressure sampling point.  If a welded joint is present w ithin 0.5 D of the 
front pressure sampling point, the third cross -section must be located at this joint.  
3.4.4    Pipe circularity and cylindricity  
The internal shape of the pipe must be circular along its entire minimum straight length.  
In straight section  up to distance  2D in front of the diaphragm plate, no internal pipe diameter may 
differ in any plane by more than 0.3 % of the mean value of the internal diameter D. 
At a distance over 2D and up to 10D  from the diaphragm  along the straight pipe section, t he difference 
in internal pipe diameters between two arbitrary pipe sections must not exceed 0.3 % of the mean 
value of the internal diameter D. At the same time, the overlap of internal diameters of adjacent pipe 
sections caused by deviation and/or change s in diameter D must not exceed 0.3 % of the mean value 
of the internal diameter D at any arbitrary point of the internal pipe circumference.  
No internal diameter of the straight section of pipe behind the diaphragm plate may differ from the mean 
internal pipe diameter D in front of the diaphragm plat by more than 3 % along at least a distance of 2 D 
from the front part of the diaphragm plate.  
3.4.5    Pipe inner surface quality  
The inner surface of the pipe must be clean and free of visible defects.  
Over th e length of the specified minimum straight section in front of the diaphragm plate, the pipe’s 
inner surface must meet specified requirements for surface roughness Ra. 
3.5    Installation requirements  
The diaphragm plate’s installation position must be uni quely determined by its design, or must be 
schematically indicated directly on the diaphragm plate.  
4    Measuring instrument labelling  
4.1    In general  
All labels and markings must be easily visible, legible and indelible under normal conditions, and 
must provide information required for error -free implementation of the diaphragm sensor for 
measuring transmission media flow into system measuring transmission media flow in connection to 
other elements of the measuring system.  
4.2   Markings  
4.2.1     Markin gs on the diaphragm plate  
The diaphragm plate must have the following information:  
– serial number;  
– the value of the inside diameter of the diaphragm opening d20 at a reference temperature of 
20 °C; 
– a type approval mark;  
– suitable markings for identifying the  type and location of differential sampling points, if 
pressure sampling is a fixed part of the diaphragm plate’s design.  Measure of a General Nature No. 0111 -OOP -C041 -13 
8 In cases where the above information is not visible after diaphragms have been installed in pipes, the 
diaphragm plate must also be eq uipped with a separate additional tag with the information in question, 
which shall be part of the diaphragm plate’s protection from unauthorized removal or replacement.  
In cases where the diaphragm plate could be installed incorrectly relative to the dire ction of 
transmission media flow, the diaphragm plate must be marked with the flow direction in a clear 
manner.  
4.2.2     Markings on a diaphragm sensor for measuring transmission media flow  
A diaphragm sensor for measuring transmission media flow must bear  the following information:  
– manufacturer name and type (version);  
– serial number and year of manufacture;  
– the value of the inside diameter of the diaphragm opening d20 at a reference temperature of 
20 °C; 
– a type approval mark;  
– nominal size DN/nominal pressu re PN;  
– indication of flow direction;  
– a suitable marking for type identification and differential pressure sampling location, if 
pressure sampling points are part of the  design of straight pipe sections;  
– the measured flow range or the maximum flow value (i f relevant).  
This information must be located on a part of the transmission flow sensor permanently attached to the 
straight pipe section 0.5D in front of the diaphragm (assembly chamber, connection flange in front of 
the diaphragm plate, straight section of pipe at most 2 D in front of the diaphragm plate).  
The following information must be on the connection flange or other location on the straight section of 
pipe after the diaphragm (at most 2 D past the diaphragm plate):  
– manufacturer name ; 
– serial number an d year of manufacture;  
– a type approval mark;  
– indication of flow direction (if a mistake could be made during installation).  
If the straight section of pipe in front of the diaphragm plate for the basic version of the transmission 
medium sensor consists of multiple pipe sections, all of these parts must bear a type approval mark. In 
general, all important separate parts of a diaphragm sensor for measuring transmission media flow 
must bear a type approval mark.  
4.3    Official markings  
Suitable locations for a type approval marking and official marking(s) must be provided.  
It must be possible to secure the diaphragm plate against unauthorized removal or replacement.  
5    Measuring instrument type approval  
The type approval process for a diaphragm sensor for me asuring transmission media flow includes the 
following tests and activities:  
– external inspection;  
– a check of geometric parameters.  Opatření obecné povahy č. 0111 -OOP -C041-13 
9 5.1   External inspection  
The following are checked during an external inspection:  
– that prescribed technical documentation is  complete;  
– that metrological and technical characteristics specified by the manufacturer in documentation 
match  technical and metrological requirements  of this legislation listed in Chapters 2 and 3;  
– the diaphragm plate, pressure sampling points and straig ht sections of pipe from the 
perspective of any physical damage or signs of corrosion incompatible with further testing; 
and 
– locations for marking  basic geometric parameters of the diaphragm sensor for measuring 
transmission media flow and locations for at tachment of official markings are determined.  
5.2    Check of geometric parameters  
5.2.1     Test equipment  
When checking geometric parameters, appropriate equipment with valid metrological traceability must 
be used.  
5.2.2     Reference ambient temperature f or tests  
5.2.2.1     Diaphragm plate  
During the test, the ambient temperature must be between 18 and 22 °C, and ambient temperature 
changes must not exceed 2  °C for the duration of the test.  Measure of a General Nature No. 0111 -OOP -C041 -13 
10 5.2.2.2     Straight pipe sections  
Pipes  ≤ DN  300: 
During the test,  the ambient temperature must be between 15 and 25 °C, and ambient temperature 
changes must not exceed 2  °C for the duration of the test.  
Pipes  > DN 300:  
During the test, the ambient temperature must be between 10 and 30 °C, and ambient temperature 
changes  must not exceed 5  °C for the duration of the test.  
5.2.3     Check of diaphragm plate geometric parameters  
The value of the inside diameter of the diaphragm opening d20 must be specified in accordance with 
requirements of article 3.2.6 at a reference tempe rature of 20  °C. 
For the diaphragm plate, the following geometrical parameters are also checked:  
– the flatness of the front side (see article 3.2.1.1);  
– the surface roughness of the front side (see article 3.2.1.2);  
– the thickness of the diaphragm opening and  the thickness of the diaphragm plate (see article 
3.2.3);  
– the bevel angle (see article 3.2.4);  
– the front edge of the diaphragm opening (see article 3.2.5);  
– the cylindricity of the diaphragm opening (see article 3.2.7);  
– the diaphragm opening surface roughn ess (see article 3.2.8).  
In the case of a diaphragm plate intended for measuring the flow of a transmission medium in both 
directions, all tests specified in article 5.2.3 must be performed for both sides of the diaphragm plate.  
5.2.4     Check of straight pipe section geometric parameters  
The value of the mean internal pipe diameter D20 must be determined in accordance with requirements 
of article 3.4.3 at a reference temperature of 20  °C. 
For straight pipe sections, the following geometric parameters are c hecked:  
– pipe straightness (see article 3.4.2);  
– the mean internal pipe diameter  value (see article 3.4.3);  
– pipe circularity and cylindricity (see article 3.4.4);  
– roughness of pipe’s inner surface (see article 3.4.5).  
In the case of a diaphragm plate intende d for measuring the flow of a transmission medium in both 
directions, all tests specified in article 5.2.4  must be performed for straight pipe sections on both sides 
of the diaphragm plate.  
5.2.5     Check of geometrical parameters of differential pressure sampling points  
Checks that requirements specified by the manufacturer for differential pressure sampling points have 
been met.  
6    Initial verification  
During initial verification of a diaphragm sensor for measuring transmission media flow and parts 
thereof, the following tests and activities are performed:  
– a visual inspection;  Opatření obecné povahy č. 0111 -OOP -C041-13 
11 – a test of metrological characteristics;  
– marking basic geometric parameters on appropriate parts of the diaphragm sensor for 
measuring transmission media flow.  
6.1    Visual inspect ion 
The following is checked during a visual inspection:  
– that the design and construction of the diaphragm sensor for measuring transmission media 
flow matches the approved type;  
– that the diaphragm plate, pressure sampling points and straight sections of p ipe are not 
physically damaged or bear signs of corrosion incompatible with further testing;  
– that markings, labels and their implementation correspond to information and requirements 
listed in the measuring instrument’s type approval certificate.  
If the diaphragm sensor for measuring transmission media flow fails the external inspection, no further 
tests are performed.  
6.2    Check of geometric parameters  
6.2.1     Test Equipment  
Appropriate equipment with valid metrological traceability must be used to chec k geometric 
parameters.  
6.2.2     Reference ambient temperature for tests  
Ambient temperature requirements pursuant to article 5.2.2 apply to testing.  
6.2.3     Check of diaphragm plate geometric parameters  
The value of the inside diameter of the diaphragm o pening d20 must be specified in accordance with 
requirements of article 3.2.6 at a reference temperature of 20  °C. 
During initial verification of a diaphragm plate, the following geometric parameters are also checked:  
– the flatness of the front side (see ar ticle 3.2.1.1);  
– the surface roughness of the front side (see article 3.2.1.2);  
– the thickness of the diaphragm opening and the thickness of the diaphragm plate (see article 
3.2.3);  
– the bevel angle (see article 3.2.4);  
– the front edge of the diaphragm opening  (see article 3.2.5);  
– the cylindricity of the diaphragm opening (see article 3.2.7).  
In the case of a diaphragm plate intended for measuring the flow of a transmission medium in both 
directions, all tests specified in article 6.2.3 must be performed for bo th sides of the diaphragm plate.  
6.2.4    Check of straight pipe section geometric parameters  
The value of the mean internal pipe diameter D20 must be determined in accordance with requirements 
of article 3.4.3 at a reference temperature of 20  °C. 
During in itial verification of straight pipe sections, the following geometric parameters are also 
checked:  
– pipe straightness (see article 3.4.2);  
– pipe circularity and cylindricity (see article 3.4.4);  Measure of a General Nature No. 0111 -OOP -C041 -13 
12 – roughness of pipe’s inner surface (see article 3.4.5).  
In the c ase of a diaphragm plate intended for measuring the flow of a transmission medium in both 
directions, all tests specified in article 6.2.4 must be performed for straight pipe sections on both sides 
of the diaphragm plate.  
6.2.5    Check of geometrical param eters of differential pressure sampling points  
Initial verification involves checking that requirements specified by the manufacturer for differential 
pressure sampling points have been met.  
6.2.6    Marking of basic geometric parameters on the measuring i nstrument  
The value of the inside diameter of the diaphragm opening d20 determined pursuant to article 6.2.3 
must be marked in a legible and indelible manner in a suitable location on the diaphragm plate.  
The value of the mean internal pipe diameter D20 determined pursuant to article 6.2.4 must be marked 
in a legible and indelible manner in a suitable location on the transmission medium flow sensor in 
accordance with article 4.2.2.  
7   Subsequent verification  
The subsequent verification procedure for a diap hragm plate is identical to the initial verification 
procedure pursuant to article 6.2.3.  
Subsequent verification of straight pipe sections of a diaphragm sensor for measuring transmission 
media flow is not performed.  
The user of the measuring instrument e nsures permanent fulfilment of service conditions, including 
keeping the internal surface of pipes in appropriate condition and clean. For this purpose, the user of 
the measuring instrument performs or arranges performance of visual checks of the internal surface of 
pipes at intervals that take into account service conditions and the type of transmission medium being  
measured. This check must also always be performed prior to the installation of a diaphragm plate.  
During testing during verification validity  pursuant to § 11(4) of Act No. 505/1990, on metrology, as 
amended, a transmission medium flow sensor is subject to  initial verification requirements that can be 
realistically applied.  
8   Notified standards  
To specify metrological and technical requiremen ts for measuring devices and to specify verification 
test methods stemming from this measure of a general nature, the CMI notifies Czech technical 
standards, other tech nical standards or technical documents of international or foreign organizations or 
other technical documents containing detailed technical requirements (hereinafter "notified 
standards"). The CMI shall publish a list of these notified standards, with thei r assignation to relevant 
measures, along with the measure of a general nature, in a manner available to the public (on the 
website www.cmi.cz).  
Compliance with notified standards or parts thereof is considered to be, to the extent and under the 
conditions  stipulated by a measure of a general nature, to be compliance with those requirements 
stipulated by this measure to which these standards or parts thereof apply.  
II. 
JUSTIFICATION  
The CMI issues, towards the implementation of § 24c of Act No. 505/1990, on  metrology, as 
amended, this measure of a general nature, stipulating metrological and technical requirements for 
specified measuring devices and test methods for verification of these specified measuring devices.  Opatření obecné povahy č. 0111 -OOP -C041-13 
13 In Decree No. 345/2002, specifying measuri ng devices for mandatory verification and measuring 
devices subject to type approval, as amended, the annex "List of Specified Measuring Device Types" 
classifies diaphragm sensors for measuring transmission media flow  under items 3.1.2 b) as measuring 
devices subject to type approval and verification.  
The CMI thus issues, towards the implementation of § 24c of Act No. 505/1990, on metrology, as 
amended, for the measuring device type specified as “ diaphragm sensors for measuring transmission 
media flow ”, thi s measure of a general nature, stipulating metrological and technical requirements for 
diaphragm sensors for measuring transmission media flow  and test methods for type approval and 
verification of these specified measuring devices.  
This regulation (Measur e of a General Nature) has been notified in accordance with Directive 
98/34/EC of the European Parliament and of the Council of 22 June 1998 laying down a procedure for 
the provision of information in the field of technical standards and regulations, as am ended by 
Directive 98/48/EC.  
 
 
III. 
INSTRUCTIONS  
A measure of a general nature cannot be appealed (§  173(2) of the Administrative Code).  
Pursuant to § 172(5) of the Administrative Code, a decision on objections cannot be appealed.  
Conformance of a measure of a general nature with legislation can be judged in review proceedings 
pursuant to § 94 to 96 of the Administrative Code. A participant may ask the administrative body that 
issued this measure of a general nature to perform a review. If the administrativ e body does not see any 
reason to commence review proceedings, it shall inform the submitter of this fact within thirty days, 
giving reasons. Pursuant to § 174(2) of the Administrative Code, a ruling on the commencement of 
review proceedings can be issued within three years of the effective date of the measure of a general 
nature.  
 
 
IV. 
EFFECTIVE DATE  
This measure of a general nature takes effect on the fifteenth day following the day of its publication 
(§ 24d of Act No. 505/1990, on metrology).  
 
 
 
...…………… ……………..............  
RNDr. Pavel Klenovský  
generální ředitel