CZECH 
METROLOGIC
AL INSTITUTE  Okružní 31, 638 00 Brno  
legmet@cmi.cz  
 +420 545 555 414  
 
 
 
1. ------IND-  2019 0302 CZ-  EN- ------ 20190703 --- --- PROJET 
Executive summary for the EC (not included in this legislation)  
“Measuring of the volume activity of 222Rn in air and water and the equivalent volume activity of 222Rn in air, both instantaneous values and short -term and long- term averages” can be marketed and 
placed on the market in the Czech Republic as specified measuring instruments  according to Act 
No 505/1990 Coll. on metrology, as amended. Specified measuring instruments are, according to this 
act, measuring instruments whose the type is specified in the generic list of specified measuring instruments (Directive No 345/2002 Coll.) and which are also determined (by the 
manufacturer/importer) to measure with the importance of protection of the public interest in the areas 
of consumer protection, obligations, sanctions, fees, tariffs and taxes, health protection, env ironmental 
protection, occupational safety or other public interests protected by special legislation. It is therefore a similar purpose to which the specified products are defined – non-automatic measuring instruments 
and instruments according to Directiv es 2014/31/EU and 2014/32/EU. The requirements of this 
Regulation do not apply to measuring instruments not placed on the market in the Czech Republic for 
the above purposes of use, as defined by Act No 505/1990 Coll.  
The subject of this notified regulatio n is the determination of metrological and technical requirements 
for specified measuring instruments of that kind. The regulation also provides for tests for type -approval 
and verification of specified measuring instruments of that kind.  
(End of management summary.)  
 
PUBLIC NOTICE  
 
The Czech Metrology Institute (hereinafter referred to as “CMI”), as the body competent and relevant 
for the determination of metrological and technical requirements for a specified measuring instrument 
and for the determination of type -approval tests and verification of a specified measuring instrument 
pursuant to § 14(1) of Act No 505/1990 On Metrology, as amended (hereinafter referred to as the 
“Metrology Act”), and pursuant to the provisions of § 172 et seq. of Act No  500/2004 Coll., the 
Administrative Procedure Code, as amended (hereinafter the “Procedure Code”), initiated on 12 February 2016 an administrative proceeding pursuant to §  46 of the Code of Criminal Procedure, and 
on the basis of the documents it issues the follow ing: 
 
I. 
DRAFT GENERAL MEASURE  
Number: 0111- OOP -C097 -18 
 
laying down metrological and technical requirements for specified measuring instruments, 
including the testing methods for verification of the following specified measuring instruments:  
 “222Rn volumetric activity measuring instruments in air and water and 222Rn equivalent 
volumetric activity in air, both instantaneous and short -term and long -term averages”  
 Measure of general nature No. 0111- OOP -C097- 18 
2 1 Basic concepts  
or the purposes of this general measure, the terms and definitions of  VIM and VIML1 and the following 
apply:  
1.1 
Activity  
The proportion of the expected value of the number of nuclear transformations from the determined 
energy state and the time interval at which these conversions occur  
1.2 
Radon volume activity (OAR)  
The ratio of activity to volume in which it is monitored (only radon 222Rn in air and water respectively 
is always referred to in this document)  
1.3 Equivalent radon volume activity (EOAR)  
Weighted sum of a 1 218Po, volume activity a 2 214Pb volume activity and a 3 214Bi; volume activity; 
equivalent radon volume activity for the purposes of this document is equal to 0.106 × a 1, 0.513 × a 2 a 
0.381 × a 3 
1.4 Daughter products of radioactive radon conversion RnDP  
Nuclides produced by the radioactive conversion of radon 222Rn and nuclides from its transformation 
series. Only short -term products are always considered in this regulation, i.e. 218Po, 214Pb, 214Bi a 214Po. 
1.5 
Balance factor F  
Expresses the degree of relative radioactive balance between radon 222Rn and its short -term conversion 
products. It is expressed by the ratio F = (EOAR) / (OAR).  
1.6 
Free fraction  
In this document, the RnDP content is meant that is not bound to the aerosol  in the air  
1.7 Aerosol  
Suspended small solid or liquid particles in the air  
1.8 Test source  
The radionuclide source (secondary standard) used to test the properties of the measuring instrument  
1.9 Control source  
The radionuclide source used to check the correct operation of the measuring instrument  
                                                      
1  TNI 01 0115 International Metrology Vocabulary –  Basic and General Terms and Associated Terms (VIM) 
and the International Vocabulary of Terms in Legal Metrology (VIML) are part of the technical harmonization 
proceedings "Terminology in Metrology" publicly available at www.unmz.cz.  Measure of general nature No. 0111- OOP -C097- 18 
3 1.10 
Reference source  
The radionuclide source that is linked to a recognised standard  
1.11 Reference atmosphere  
The radioactive atmosphere in which the influencing parameters (aerosol content, volumetric activi ty, 
temperature and humidity of the air, etc.) are sufficiently known or controlled to allow testing of OAR 
or EOAR measuring instruments. A reference atmosphere maintaining device is usually referred to as a radon chamber (or a test room).  
1.12 
Standard atmospheric conditions  
Climatic conditions corresponding to an air temperature of 0 °C and pressure of 101 325 Pa  
1.13 Continuous measurement method 
Method, which ensures permanent recording of measured parameters for the defined measurement time, 
the time  resolution is adapted to the examined phenomena  
1.14 
Integral method of measurement  
A method that determines the integral of a measured quantity over a sampling period (or sampling time: 
averaged over time)  
1.15 
Integrating measurement method  
A method in which instantaneous or short -term values are determined, but the output of the measurement 
is the time integral of the measured quantity  
1.16 Relaxation time (diffusion)  
The time at which 63.2 % equilibrium is reached during diffusion  
2 Metrological requir ements  
Metrological requirements for meters of instantaneous values and medium and long -term averages of 
radon volume activity, equivalent radon volume activities in air are taken from European standards.  
2.1 Quantities and units  
The measuring instrument must allow measurements in the legal SI units. If the country of origin is 
outside the European Union and the measurement result is indicated in local (historical) units, the 
importer must indicate the formula or procedure by which the measuring instrument is transferred to SI 
units. If it is a contractual quantity (EOAR or other contractual quantity), the supplier must give a precise 
definition of this quantity according to SI units (reference to this document or a valid radiation protection 
document for the Czech Republic is sufficient). If the measuring instrument indication provides results in the “latent energy concentration” and quantities derived therefrom, the supplier must specify the 
measurement conditions and the method of  converting the result to activity quantities and what is 
derived, always in SI units. Unless otherwise stated, this procedure can only be found in the instruction Measure of general nature No. 0111- OOP -C097- 18 
4 manual; however, an automated procedure is preferred (internal measuring instrument program or 
computer software provided).  
2.2 Classification of measuring instruments  
The manufacturer must specify for which purpose the measuring instrument is intended.  
The classification must include the following:  
a) measured quantity (OAR, EOAR, radon volume activity in water; if the measuring instrument is intended for the determination of 
220Rn, the manufacturer must notify of this fact separately),  
b) expected environment of use (outdoor air, air of living and working  rooms and other premises, 
mine air, radon in soil air),  
c) time and method of measurement (instantaneous values, air sampling with subsequent sample measurement, measurement of integral value, continuous sampling),  
d) method of sampling (e.g. diffusion, pumping ), 
e) method of detection and counting (e.g. α particle counting, α spectrometry, total ionisation, surface disruption with optical failure count),  
f) method of calculation (e.g. deconvolution of conversion equation, use of alpha spectrometry),  
g) normal operating conditions. 
2.3 Measuring range  
The measuring instrument must ensure, within the permissible error, measurement at least to the extent 
specified by a special legal regulation.2 
2.4 Specified working conditions  
The manufacturer must determine for what purpose the measuring instrument is intended (see 2.2.b). Unless otherwise specified by the manufacturer, the measuring instrument must comply with the 
climatic conditions given in Table  1 below.  
Table  1 – Climatic conditions  
Influence 
quantity  Required range  
Use Outdoors  Indoors  Underground  Soil air  
Temperature  −40 °C to +60  °C +5 °C to +40  °C 0 °C to +60  °C -10 °C to +50  °C 
Relative humidity  10 % to 100  % 
(condensing)  10 % to 70 % 10 % to 100  % 
(condensing)  80 % to 100  % 
(condensing)  
Atmospheric 
pressure  86 kPa to 106 kPa  
If the sampling and measuring response processes are separate, the table applies only to the sampling 
portion. In this case, the manufacturer may specify the measurement part parameters differently.  
                                                      
2  Directive No  422/2016 Coll., O n Radiation Protection and Radionuclide Source Security  
 For immediate OAR measuring instruments used to determine the plot's radon index, the measuring range 
is at least (10 to 100) kBq/m3. 
 For OAR average value measuring instruments used to determine the radon content of living or residential 
buildings, the range is at least (50 to 3  000) Bq/m3. 
 If the EOAR is used to check compliance with applicable radiation protection requirements (conversion to 
OAR), the measuring range must meet the previous requirement after recalculation.  Measure of general nature No. 0111- OOP -C097- 18 
5 2.5 Maximum permissible error  
The maximum permissible relative internal error is ±20  %. It is determined under standard test 
conditions (air temperature +5 °C to +40 °C, relative air humidity 50  % to 75  %, atmospheric pressure 
86 kPa to 106 kPa, dose rate of external γ radiation less than 0.25 µGy/h). 
The additional deviation under extreme climatic conditions and in the event of a change in the supply 
voltage defined by the manufacturer must not exceed ± 10 % for any test . 
2.6 Minimum detectable volume activity  
The required minimum detectab le radon volume activity depends on the particular application and 
conditions. The manufacturer is obligated to specify it explicitly. 
2.7 Indirect measurement  
If the value is determined indirectly by calculation, the manufacturer must simply indicate the 
calculation procedure including the relevant uncertainty. If the calculation method is not entirely 
obvious, references to literature must be given and the principle of determining the quantity must be 
described.  
2.8 Measurement of radon 222Rn radial activity in water  
Due to radon's physical properties, its measurement in water is always an indirect measurement. Radon 
measuring instruments in the air transferred from water are subject to the same requirements as radon 
measuring instruments in the air. Radia tion measuring instruments γ of radioactive radon conversion 
products are subject to requirements for spectrometric measuring instruments γ.  
3 Technical requirements  
3.1 Mechanical performance requirements  
The mechanical resistance must be appropriate for the purpose and method of measurement (see 2.2.b). 
If long- term placement in occupied spaces or in premises randomly visited by untrained persons is 
envisaged, the mechanical design must be reasonably resistant to unauthorised interference, or the 
apparatu s must allow detection of such interference and elimination of measurements. Due to the wide 
range of use of different types of such measuring instruments, mechanical resistance tests cannot be listed exhaustively.  
3.2 Air supply  
If an air circuit with a p ump is used for EOAR measuring instruments, the device must allow assessing 
the flow volume or determining the flow rate. The pump must ensure a reliable flow even when the filter 
is plugged in, or it must terminate the measurement and signal a fault if th e filter is clogged above the 
permissible limit. Access to the sampling part of the measuring instrument must ensure taking the sample not influenced by the environment (according to the environment for use of the measuring instrument 
specified by the manu facturer).  
If the air supply to the detection area is performed discreetly, the measuring instrument must include an 
element that ensures the correct volume of injected air. This requirement can be provided by an auxiliary 
device, for example a calibrated vessel. The manufacturer must determine the procedure to ensure 
correct air sample metering. The dosage can be automatic or manual.  
For devices with diffuse air supply to the measuring instrument detection area, the manufacturer must 
determine the correct procedure for positioning the measuring instrument and protecting the input 
components to ensure uniform diffusion.  Measure of general nature No. 0111- OOP -C097- 18 
6 EOAR measuring instruments must ensure free RnDP fraction access to the detection area, or the 
manufacturer must provide quantification of t he free fraction effect.  
3.3 Power supply 
For measuring instruments that are supplied from the mains at the time of measurement, the manufacturer must indicate the nominal values and the permissible range of voltage and frequency 
deviations. Any additional  error caused by changing power conditions within this range must not exceed 
10 %.  
For measuring instrument s that are powered by batteries (primary sources or accumulators) at the time 
of measurement, the manufacturer must indicate the minimum guaranteed operating time when using 
these sources. The change in the indicated value over the life of these sources may  not exceed 10 %. 
When the passive detector evaluation device is powered by batteries, it must allow checking the supply 
voltage or functionality.  
3.4 Resistance of equipment to external influences  
The use of radon measuring instruments includes all internal and external environments. The extent and type of external influences and the degree of resistance to them must be specified by the manufacturer.  
3.5 Electromagnetic environment  
The manufacturer must determine for which environment the equipment is inte nded. The required 
electromagnetic interference resistance is determined by the general environmental regulations specified 
by the manufacturer.  
Devices with passive detectors (trace detectors, electrets) are not subject to any electromagnetic 
resistance r estrictions.  
3.6 Measuring instrument safety and fraud protection  
It must be possible to block access to controls (for example, by using a password) when the measuring instrument is used for institutional measurements.  
4 Measuring instrument marking 
4.1 Marking on the measuring instrument  
A rating plate must be affixed to the measuring instrument, containing at least the following information:  
a) Type and production number;  
b) In the case of an external power supply, the supply voltage (in the case of AC, the frequency 
must be 50 Hz);  
c) Approval mark. 
4.2 Placing of the official mark  
The official mark must be placed in such a way as to be accessible to any inspection. As a rule, in compact measuring instruments, they are located near the controls on the front. For remote access 
systems, the placement of two official marks is appropriate;  the main one should be located on the 
control unit.  
For each instrument type, the location of the official mark must be specified in the Type Approval Certificate.  Measure of general nature No. 0111- OOP -C097- 18 
7 5 Measuring instrument type-approval  
During type -approval, the following tests are performed:  
a) External inspection,  
b) Linearity response test (accuracy of data at different values of measured quantity),  
c) Long- term stability test,  
d) Temperature and humidity dependence,  
e) Measuring instrument response dependence on RnDP content (on F  coefficient value),  
f) Diffusion rate into the measuring chamber when the air supply is diffusion,  
g) γ radiation dependence test if a γ -sensitive detector is used,  
h) Test the properties of the air cir cuit if it is part of the measuring instrument,  
i) Other tests to check the metrological properties declared by the manufacturer (influence of 
aerosols, special way of operating the measuring instrument, etc.).  
5.1 External inspection  
The following is assessed during external inspection:  
a) the completeness of the prescribed technical documentation pursuant to §  6(2) of Act 
No 505/1990 Coll. on metrology, as amended;  
b) the completeness and condition of the measuring instrument or assembly according to the 
technical  documentation supplied.  
5.2 Test conditions during type -approval  
Tests conducted during reference conditions must be conducted on the following conditions (normal test 
conditions):  
 Rise time ≥ 10 minutes;  
 Ambient temperature (18 to 22)  °C; 
 Relative air hu midity (50 to 75)  %; 
 Dose equivalent rate in the environment (background) < 0.25 µSv/h;  
 Air pressure (86 to 106)  kPa;  
 Power voltage  UN ± 0.5 %; 
 Flow rate through air circuit -  nominal flow rate ± 5  % (if air circuit is used);  
 Controls set for normal operation.  
5.3 Basic functional tests  
5.3.1 Response linearity test or accuracy data at different values of OAR (EOAR)  
According to the method of sampling or transfer of the measured air, a known OAR (EOAR) value is 
applied to the air measuring instrument.  
a) Measuring instruments for discontinuous measurement. 
Air with a known OAR (EOAR) is injected into the measuring volume. At least four 
measurements must be made for the entire measurement range so that the lowest value is not 
greater than 10 times the decl ared lower limit of the measuring range (or 10 times the predicted 
lowest level according to paragraph  2.3). If it is not possible to reach the upper limit of the 
measuring range within the test facility, the highest achievable value must be used and indic ated 
in the test report.  
b) Measuring instruments for continuous measurement (also measuring instruments for step measurement – measurement at predefined time intervals).  
These are instantaneous values or measuring instrument integrating from a set of instant aneous 
values. The measuring instrument is located in the radon chamber (or test room) and the OAR (or EOAR) values are set within the required test range (measuring range). The test must be 
performed at a minimum of four points under the same conditions a s in 5.3.1.a). The Measure of general nature No. 0111- OOP -C097- 18 
8 measurement time must be sufficient to stabilise the measuring instrument indication. The values 
can be set in any order; the indication must always be stable before the change. If the measuring 
instrument integrates the results as an av erage of the measurement time, the time must be at least 
according to the set integration time for each measurement.  
c) Integral value measuring instruments.  
The test is carried out as in 5.3.1.b); the OAR (EOAR) waveform must be known (preferably 
constant) throughout one measurement. It must be possible to evaluate the measuring instrument 
indication between measurements. The exposure time of the measuring instrument to the reference atmosphere must correspond to the measurement method, especially due to the possible 
diffusion time of the atmosphere to the measuring volume. For measuring instruments designed for a long integration time (e.g. week or year), exposure time can be proportionally reduced and 
proportionally increased by the OAR (EOAR) used if the m easurement principle permits.  
The measuring instrument error in any measurement must not exceed 20  %. 
5.3.2 Long- term stability test  
Since the measuring time varies from one second to one year for the purpose and design of the measuring instrument, the test procedure cannot be precisely specified. The aim of the test is to demonstrate that 
the measurement results are reproducible for at least 100 hours.  
a) Measuring instruments for discontinuous measurements must be tested at least 1, 2, 10, 50 and 
100 hour s after the start of the test. The response to a fixed reference source simulating the 
measured sample from the air can be determined.  
b) Continuous response measuring instruments (instantaneous OAR or EOAR values) are tested in 
a radon chamber (test room) for at least 100 hours. A constant OAR (EOAR) value can be 
maintained during this period, or the value can be variable and compared to a reference value. 
The meter indication must be compared at least for the same time as for the discontinuous 
measuring inst ruments. This test may be part of the test in 5.3.1. A fixed reference source can be 
used for the test if the measuring instrument design permits. 
c) Integral measuring instruments must be tested so that the start of individual measurements is at 
least as spe cified in 5.3.2 a. The test procedure must be modified according to the physical nature 
of the measurement and the design of the measuring instrument.  
The measurement deviation at time t = 0 must not exceed 10 %. 
5.3.3 Influence of climatic conditions  
This test is carried out in a climatic chamber or in a radon chamber with controlled temperature and 
humidity. Sample or capture measuring instruments in a suitable medium (containing activated carbon 
or another absorbent) must be exposed to the test atmospher e during the test. Other measuring 
instruments can be tested using a control source. The tests are carried out separately for the influence of temperature and the effect of air humidity. 
The measuring instrument is placed in the test equipment under standa rd test conditions and the response 
is read after a balanced response (at least 10 minutes). Thereafter, the climatic resistance limit value is 
set and the response subtracted once equilibrium has been reached. The temperature gradient must not 
be greater than 2  °C per minute. Humidity dependence is determined at a constant temperature of + 
30 °C. If the manufacturer determines a different method of handling, it must be observed.  
The setting time of the thermal balance depends on the construction (weight) o f the measuring 
instrument and a shorter time than 1 hour must not be selected. If a vacuum electronic element 
(photomultiplier) is included in the measuring instrument, this time must not be less than 3 hours.  
The range of resistance in climatic condition s is determined by the purpose of the measuring instrument's 
use in paragraph 2.4.  
Deviations from the standard test conditions must not exceed 10 % for any of the tests and limit values.  Measure of general nature No. 0111- OOP -C097- 18 
9 5.3.4 Effect of balance factor F on measuring instrument response  
It is not necessary to test the influence of RnDP on the measuring instrument's response in OAR 
measuring instruments where the physical measurement principle or the prescribed method excludes 
this dependence. These are measuring instruments that contain an effective aerosol filter at the entrance 
to the detection section, measuring instruments that have a prescribed delay between air sampling and 
the start of the measurement of at least 210 minutes, and measuring instruments whose sensitive volume 
enters air  by diffusion with a relaxation time of at least 90 minutes.  
The test is carried out by placing in a radon chamber at a sufficient distance (at least 0.3  m) from the 
chamber walls. The number of aerosol particles should be in the range of (108 to 1012) m-3, if permitted 
by the radon chamber. The test must be conducted with at least five F  values, with individual values at 
intervals (0.0 to 0.2), (0.2 to 0.4), (0.4 to 0.6), (0.6 to 0.8), (0.8 to 1.0). The measurement must continue 
until the equilibrium indic ation is reached.  
Deviation from measuring instrument data for any of the measured points must not exceed 20  %. 
5.3.5 Diffusion speed test  
This test is performed only for instruments with diffuse air exchange and with immediate reading of the indication. For the purpose of this regulation, it is sufficient to decide if the diffusion rate (described by 
the relaxation time) is greater than 90 minutes.  
The measuring instrument is placed in the radon chamber and after the OAR step change, response values are r ead at least 210 minutes at intervals of at least 30 minutes. From the measured values, the 
relaxation time is determined by fitting the measured points with the exponential function. The 
relaxation time is a constant at the time variable of the exponential function.  
5.3.6 Radiation γ dependence test  
The change in measuring instrument response under standard test conditions (dose rate <0.2  µGy/h) and 
when irradiated with a dose rate of 1 µGy/h caused by a 
137Cs source must not exceed the value given 
by the manufacturer. Exceptionally, a source simulating a gamma -ray natural spectrum (with preferred 
content of 226Ra) may be used.  
5.3.7 Air circuit properties test  
The air circuit must guarantee constant air flow  and be sufficiently tight. If the flow or volume of air 
flow is used to determine volumetric activity (sampling on a filter or absorbing medium), the flow rate 
or volume flow must be determined correctly. 
A calibrated flow meter is connected to the air ci rcuit. After 30 minutes, the measured flow deviation 
must be less than ± 10  % of the initial value. The test must be carried out within a further 5 and 20 hours 
of operation; the additional error against the first measurement must not exceed ± 10 %. If the  flow or 
volume is used to determine volumetric activity, a comparison is made with the value determined by the 
calibrated flow meter with the same requirements.  
The leak test is performed using two calibrated flow meters located upstream and downstream of  the 
filter. The deviation must not exceed ± 10 %. If this test cannot be performed, the pressure drop test may 
be used and the leak volume calculated at the normal measuring time (measuring interval).  
5.3.8 Electromagnetic immunity and interference  
The me asuring instruments must be designed and manufactured in a way that ensures, with due regard 
for the state of the art, that  
a) the electromagnetic disturbances they cause do not exceed the level at which radio and 
telecommunications equipment or other equipme nt is not capable of functioning in accordance 
with its intended use and  Measure of general nature No. 0111- OOP -C097- 18 
10 b) achieve a level of immunity to the electromagnetic disturbance expected in their operation in 
accordance with the intended use, which allows them to function without unacceptable 
degradation of operation in accordance with the intended use.  
6 Initial verification  
These measuring instruments are subject to initial verification in accordance with Act No  505/1990 Coll. 
on metrology, as amended, as regards a new or repaired measuring instrument. 
6.1 Visual inspection  
During the visual inspection, it is checked whether the device is obviously damaged.  
6.2 Functional tests  
6.2.1. Test equipment accuracy requirements  
The measuring instrument used to check the volume or flow must have a measurement accuracy that is 
better than ± 5  %. The OAR (or EOAR) calibration standard must have an uncertainty of less than 10  %. 
6.2.2. Tests of linearity response and measurement accuracy in the measuring range  
The test must be carried out according to the procedure described in paragraph 2.3.1. If it is sufficient 
to verify the correctness of the measurement to a lesser extent than the intended measurement range for 
the intended use of the measuring instrument and the tests have been performed to a limi ted extent, this 
must be stated in the verification document. 
7 Subsequent verification  
For subsequent verification, the same tests are performed as for initial verification.  
8 Testing the measuring instrument  
When testing the measuring instruments pursuan t to §  11a of the Metrology Act at the request of a 
person who may be affected by its incorrect measurement, the procedure of Chapter  7 must be followed. 
The maximum permissible errors are 1.25 times the maximum permissible errors according to 
Chapter  7. 
9 Notified standards  
For the purpose of specifying metrological and technical requirements for measuring instruments and for the purpose of specifying test methods for type -approval and verification, resulting from this measure 
of a general nature, CMI must notify Czech technical standards, other technical standards or technical 
documents of international or foreign organisations or other technical documents containing more 
detailed technical requirements ("notified standards"). The CMI together with the measure of a general 
nature will publicly disclose the list of these notified standards with the relevant measure in a publicly 
accessible manner (on the website) www.cmi.cz
). 
Compliance with the notified standards or compliance with parts thereof must be deemed, to the extent 
and under the conditions laid down in this measure of a general nature, to meet those requirements laid 
down in this me asure to which those standards or parts thereof relate.  Measure of general nature No. 0111- OOP -C097- 18 
11 Compliance with a notified standard is one way to demonstrate compliance. These requirements may 
also be met by other technical solutions guaranteeing the same or a higher level of protection of 
legitimate interests.  
II. 
GROUNDS  
Pursuant to § 14(1)(j) of the Metrology Act, CMI issues §  6(2), §  9(1) and (9) and § 11a(3) of the 
Metrology Act with this measure of a general nature, laying down metrological and technical 
requirements for specified measuring  instruments and tests at type -approval and for verification of 
specified measuring instruments - “222Rn volumetric activity measuring instruments in air and water and 
222Rn equivalent volumetric activity in air, both instantaneous and short -term and long- term average”.  
Decree No  345/2002 Coll., by which measuring instruments for compulsory verification and measuring 
instruments subject to type -approval, as amended, includes the listed type of measuring instruments 
under item  8.4 in the Annex of the List of  measuring instruments and between measuring instruments 
subject to type -approval and mandatory verification.  
This legislation (Measure of a General Nature) will be notified in accordance with Directive (EU)  2015/1535 of the European Parliament and of the Council of 9 September  2015 laying down a 
procedure for the provision of information in the field of technical regulations and of rules on information society services.  
 
III. 
INSTRUCTIONS  
In accordance with §  172(l) APC in conjunction with §  39(l) APC, the  CMI has stipulated a time limit 
for comments of 30 days as of the date of posting the draft on the official notice board. Comments 
submitted after this time limit will not be considered.  
The persons concerned are hereby invited to comment on this draft Me asure of a General Nature. With 
regard to the provisions of § 172(4) of the code, comments are submitted in writing and must meet the requirements of filing pursuant to § 37 of the code.  
The comments must have the particulars specified in §  37(2) of the code, it must be clear who is making 
them, against which measures of a general nature are directed, to what extent they contest it and what is 
considered a contradiction with legal regulations or incorrectness of a measure of general nature or 
procedure whic h precedes it, which matters concern it and what it proposes, must include the designation 
of the administrative authority to which it is addressed and the signature of the person who makes it.  
The supporting documents for this draft general measure may be  consulted at the Czech Metrology 
Institute, Legal Metrology Department, Okružní 31, 638 00 Brno, after making arrangements by 
telephone.  
This draft general measure shall be posted for 15  days.  
 
 
Czech Metrology Institute  
Director General