Czech Metrology Institute  
Okružní 31, 638 00  Brno  
 
1. ------IND- 2018 0578 CZ - EN- ------ 20181213 --- --- PROJET 
Author: Mgr. Tomáš Hendrych  
Telephone: +420 545 555 414  
 
Executive summary for the EC (not part of this legislation)  
'Measuring instruments used to monitor activity limits and volume activity o f effluents from nuclear 
facilities, nuclear raw material mining or processing facilities, radioactive waste processing plants 
and from the processing or application of radioactive materials, and also used to determine 
environmental radiation exposure due to effluents – measuring instruments for the continuous 
monitoring of radioactive aerosols including transuranic aerosols in gaseous effluents from nuclear 
facilities ’ may be placed on the market and put into use in the Czech Republic as specified measurin g 
instruments  pursuant to Act  No 505/1990 on metrology, as amended. In accordance with this Act, 
specified measuring instruments are measuring instruments whose type is specified in the  'List of 
Specified Measuring Device Types' (Decree  No 345/2002) and w hich are specified (by the 
manufacturer or importer) for measurements relevant to the protection of public interest in fields of 
consumer protection, contractual relations, stipulation of sanctions, fees, tariffs and duties, health 
protection, environmenta l protection, occupational safety or protection of other public interests 
protected by separate legislation.  This is the same purpose of use by means of which specified 
products are defined – measuring instruments and scales with non -automatic operation pu rsuant to 
Directives  2014/31/EU and 2014/32/EU. The requirements of this regulation do not apply to 
measuring instruments which are not placed on the market in the Czech Republic for the above -
mentioned purposes of use, defined by Act  No 505/1990 on metrol ogy. 
The subject of this notified regulation is to lay down metrological and technical requirements for 
specified measuring instruments of the above -mentioned type. This regulation also stipulates tests for 
type-approval and verification of measuring instr uments of the above -mentioned type.  
(End of executive summary.)  
 
P U B L I C  N O T I C E 
 
As the authority with substantive and territorial jurisdiction in the matter of laying down metrological 
and technical requirements for legally controlled measuring instruments and stipulating the testing 
methods for type -approval and verification of legally controlled measuring instruments pursuant to 
§ 14(1) of Act  No 505/1990, on metrology, as amended (hereinafter the ‘Metrology Act ’), and in 
accordance with the pr ovisions of §  172 et seq. of Act  No 500/2004, the Code of Administrative 
Procedure (hereinafter the ‘CAP ’), the Czech Metrology Institute (hereinafter the ‘CMI ’) commenced 
ex officio proceedings on 12  February  2016 pursuant to §  46 of the CAP, and, based o n supporting 
documents, issues the following:  
 General Measure No  0111 -OOP -C074 -16 
2 I. 
D R A F T   G E N E R A L  M  E A S U R E 
number: 0111 -OOP -C074 -16 
laying down the metrological and technical requirements for legally controlled measuring 
instruments, including testing methods for verifica tion of the following legally controlled 
measuring instruments:  
 
‘measuring instruments used to monitor activity limits and concentration of effluents 
from nuclear facilities, nuclear raw material mining or processing facilities, 
radioactive waste processi ng plants and from the processing or application of 
radioactive materials, and also used to determine environmental radiation exposure 
due to effluents – measuring instruments for the continuous monitoring of radioactive 
aerosols including transuranic aero sols in gaseous effluents from nuclear facilities ’ 
 
1 Basic definitions  
For the purposes of this general measure, terms and definitions pursuant to VIM and VIML1 as well as 
the terms and definitions stated below shall apply.  
1.1 
gaseous effluent monitor  
device intended for the continuous monitoring of radioactivity in gaseous effluents; individual parts of 
the device may be connected to two component devices, which may be connected or separated 
according to monitoring and operational requirements  
1.2 
aeroso l monitor  
device intended for continuous, delayed or subsequent measurement of aerosol activity in gaseous 
effluents released into the environment  
1.3 
aerosol  
suspension of solid or liquid particles in air or gas  
1.4 
detection device  
encompasses one or mor e radiation detectors and associated functional units  
1.5 
control and evaluation device  
includes devices and functional units for measuring quantities associated with ionising radiation 
(activity, volume activity, etc.); the device has functional units for  detecting clear warnings that the 
measured quantity exceeds the predetermined value  
                                                      
1  TNI 01 0115 International Vocabulary of Metrology – Basic and General Concepts and Associated Terms 
(VIM) and International Vocabulary of Terms in Legal Metrology (V IML) are part of the technical 
harmonisation compendium ‘Terminology in the Area of Metrology ’, which is publicly accessible at 
www.unmz.cz  General Measure No  0111 -OOP -C074 -16 
3 1.6 
coefficient of variation  
ratio V of standard deviation s and arithmetic mean of the x set of n measurements xi, given by the 
relationship:  


n
iixx
nxxsV
12) (
11 1
 (1) 
1.7 
detection limit LD 
measured value of the quantity obtained by the given measurement process, for which there is a 
probability of an inaccurate statement on the absence of an element in material β, where the 
probability of an inaccurate statement on its presence is α 
In a sample with an actual content value of LD, only 5  % of the measurement will be inaccurately 
declared as being indistinguishable from the background (type  II error, β). Error β will equal precisely 
error α (type  I error) of the background measurement, in which 5  % of the background measurement 
will exceed the detection limit. Implicit values for α and β equalling 0.05 are recommended.  
Establishing the detection limit LD : 
LD = 1.64 5
)(2Bu (3) 
in which  B  ......  is the background value,  
 t  .............   is the time of the background measurement,  
 u(B)  .......  is the standard background deviation  
u(B) = 
tB  (4) 
1.8 
coefficient of expansion  
numeric coefficient ( k) used as th e multiple of combined standard uncertainty to obtain the expanded 
uncertainty  
1.9 
decision quantity  
variable quantity used to decide whether the physical phenomenon in question is or is not present  
1.10  
decision level  
fixed value of the decision quantit y with which it is possible to decide that the given physical 
phenomenon is present if the result of the current measurement of the physical phenomenon is 
exceeded  
1.11  
effective measuring range of the meter  
the range of values of the measured activity in which the properties of a part of the device or system 
meet the requirements of the specifications  
1.12  
dynamic range  
signal ratio at the maximum measurable quantity value and the signal at the decision level  General Measure No  0111 -OOP -C074 -16 
4 1.13  
indication error  
difference between the in dicated value of the quantity  and the conventionally correct value of this 
quantity c at the measurement point  
 =  – c (5) 
1.14  
relative fundamental error  
the relative error of the indication ei of the part of the device or system with respect to t he given 
quantity at specified reference radiation and under specified reference conditions, expressed as:  
 
 
cc
ie   (6) 
where:    .........   is the indicated value of the quantity,  
 c  ........   conventional value of the quantity at the measurement point.  
1.15 
response time  
is the time needed after a sudden change in the measured quantity in order for the change in the output 
signal to first reach the given relative value, usually 90  % of the final value  
1.16  
monitor sampling efficiency  
is defined as the rati o of volume activity accessible to measurement on a capture medium and the 
volume activity in the air at the monitor input; it is the sum of the capture efficiency and air circuit 
monitor efficiency  
1.17  
capture efficiency  
is defined as the ratio of the to tal activity accessible to measurement on the capture medium, such as a 
filter or charge of activated carbon, and the total activity in the air at the input of the capture medium  
1.18  
air circuit monitor efficiency  
describes the loss of activity on the wal ls of the monitor between the input to the circuit and the 
capture medium; it is defined as the ratio of the total activity available for monitor sampling and the 
total activity in the air at the input to the monitor  
1.19  
reference response  
under standard test conditions is given by the relation  
crefAAR
  (7) 
where:  A ..........   is the volume activity value indicated by the test device or system,  
 Ac ........   conventional volume activity value  General Measure No  0111 -OOP -C074 -16 
5 1.20  
sensitivity  
is the ratio of the value obtained by the measureme nt to the conventional activity value  
AB-IS
  (8) 
where:  I ...........   is the value indicated when measuring a radioactive sample;  
 B ..........   is the value indicated when measuring without a radioactive sample;  
 A ..........   is the conventional value of the activity of  the sample measured  
1.21  
volume activity  
activity per volume unit of air or gas  
1.22  
units  
other than the statutory units, the following secondary units are used when appropriate:  
 for time: year (y), day (d), hour (h), minute (min);  
 for energy: electronvo lt (eV);  
 for volume activity: Becquerel per cubic metre (Bq/m3) 
1.23  
classification of aerosol effluent monitors  
The devices can be classified by measuring method, such as:  
 total beta aerosol monitors;  
 total alpha aerosol monitors;  
 total alpha aerosol moni tors and total beta aerosol monitors;  
 monitors with alpha spectrometry.  
They may also be classified by method of operation, such as:  
 devices with static filter converter and simultaneous measurement;  
 devices with mobile filter converter and simultaneous me asurement;  
 devices with mobile filter converter and delayed measurement;  
 devices with mobile filter converter and simultaneous and delayed measurement;  
 devices with static filter converter and simultaneous measurement combined with mobile filter 
converter and simultaneous and/or delayed measurement.  
2   Metrological requirements  
2.1   Defined operating conditions  
An aerosol monitor must meet the metrological requirements in the range of work temperature and 
relative air humidity specified by the manufacture r.  
2.1.1    Reference conditions and standard test conditions  
The reference conditions and standard test conditions are listed in Table  1. General Measure No  0111 -OOP -C074 -16 
6 Table 1 – Reference conditions and standard test conditions  
Influencing variables  Reference conditions  Standard test conditions  
Ambient temperature  20 °C 18 °C to 22  °C 
Relative air humidity  65 % 50 % to 75 %  
Air pressure 1) 101.3  kPa 86 kPa to 106  kPa 
Supply voltage 2) Nominal supply voltage UN UN ±1 % 
Alternating supply voltage 
frequency 2) Nominal frequency  Nomin al frequency ±0.5  % 
Alternating supply voltage flow 2) Sinusoidal  Sinusoidal with a total harmonic 
distortion of less than 5  % 
Background gamma radiation  Input air kerma 0.20  Gy/h  Input air kerma 0.25  Gy/h  
Electrostatic fields  negligible  negligible  
External electromagnetic field  negligible  less than the smallest value causing 
interference  
External magnetic field  negligible  less than twice the Earth's magnetic 
field value  
Sampling flow speed  Set to nominal flow rate (specified 
by manufacturer)  Set to nominal flow rate ±5  % 
Control elements  Set for normal mode  Set for normal mode  
Radionuclide contamination  negligible  negligible  
Radon daughter products (222 and 
220) negligible  negligible  
Chemical product contamination  negligible  negligible  
1) If the detection method is particularly sensitive to changes in pressure, the conditions are limited to ±5  % of 
the reference pressure.  
2) DC supply may be used, in which case the frequency is not specified.  
2.2   Measuring range  
The measurement range of  the aerosol monitors is set by the manufacturer.  
2.3   Instrument accuracy  
The manufacturer must establish the ratio between the value on the measuring device and the activity 
of the reference source, when the device is operating at standard test conditio ns and is set according to 
the manufacturer ’s instructions. The reference response uncertainty must be specified. The reference 
response may not differ from the values specified by the manufacturer by more than 20  %.  
2.4   System linearity  
At standard tes t conditions, the relative error of indication must be less than ±10  % for the entire 
effective measurement range. Uncertainty of radioactive sources is not included. If fixed sources are 
being used, then  and c relate to sensitivity when calculating rel ative error.  
2.5   Change in detection efficiency as function of beta radiation energy (beta aerosol 
monitors)  
The change in the device ’s detection efficiency may not exceed the limits specified by the 
manufacturer. The manufacturer must specify the monito r’s behaviour for energy less than 150  keV General Measure No  0111 -OOP -C074 -16 
7 upon request. A typical calibration curve indicating the change in detection efficiency with beta 
radiation energy must be provided with each device. The manufacturer must specify the beta radiation 
energies selec ted. The thickness and type of materials between the filter and the sensitive volume of 
the detector must be specified. The results must be expressed as the ratio of the instrument ’s indicated 
unitary surface emission input specification for the given beta  radiation source used to the indicated 
unitary surface emission input specification for the reference beta radiation source.  
2.6   Response to radioactive gases  
The manufacturer must specify the response to the respective radioactive gases present in the sample 
of air or carrier gas.  
2.7   Response to daughter products 222Ra 
Since the relationship between response to daughter products of radon and the decision level and both 
parameters usually depends on the given use in operation, the response to daughter  products of radon 
and the decision level must be agreed upon by the manufacturer and the user.  
2.8   Particle collection efficiency  
The manufacturer must specify the collection efficiency of the sampling device for particles of a range 
of at least 0.1 , to 10 of the aerodynamic equivalent of the average or, for other values, according to 
the agreement between the manufacturer and user. The efficiency values are specified for standard 
operating conditions, such as for air sampling flow rate  
2.9   Respons e to ambient gamma radiation  
Since the relationship between response to ambient gamma radiation and the decision level and both 
parameters usually depends on the given use in operation, the response to gamma radiation and the 
decision level must be agreed upon by the manufacturer and the user. The manufacturer must specify 
the decision level and the maximum indication level when a detector with elements for protection 
from ambient gamma radiation is irradiated in the position specified by the manufacturer w ith a 
sudden change in input air kerma from the reference background input air kerma to 10 Gy/h for 
radionuclide 137Cs. The response to irradiation with gamma radiation at any orientation and any 
gamma radiation energy up to 1.3  MeV (radionuclide 60Co) ma y not exceed two times the value of the 
decision level.  
2.10   Overloading  
Unless the manufacturer and user agree otherwise, the device must indicate a specification off the 
scale at its upper end or indicate overloading when irradiated with a source with an activity (or surface 
emission input) 10 times greater than that corresponding to the maximum measurement range, and 
then function normally after the overloading is eliminated.  
2.11   Detection and evaluation device uptake time  
When irradiated with a rad iation source, the device must indicate a value which will not vary by more 
than ±10  % from the value obtained under standard conditions in a period of up to 30  minutes after 
being switched on.  
2.12   Statistical fluctuation  
In light of the statistical na ture of radiation, the values read out may fluctuate around the mean value. 
The coefficient of variation of the activity value caused by the statistical fluctuations must be less than 
10 % for values exceeding the first increment of 10 on the effective mea surement range.  General Measure No  0111 -OOP -C074 -16 
8 2.13   Stability of values on detection and evaluation device  
The specification indicated with the given radiation source after 30  minutes of device operation may 
not change by more than 10  % for the next 100 hours.  
2.14   Flow rate stabili ty 
The purpose of this test is to establish the nominal flow rate of sampling and the stability of sampling 
under standard test conditions with a loss of pressure caused only by the air circuit and input or 
sampling filter (clean filter). The manufacturer must specify the nominal flow rate for the filter type 
used. After the standard sampling device uptake time (30  minutes), the indicated sampling flow rate 
may not differ by more than ±10  % from the conventional flow rate value and the sampling flow rate 
may not change by more than 10  % for the next 100 hours.  
2.15   Influence of pressure loss on the filter  
Because the influence of the filter properties and the degree of blockage may vary from test to test, 
only the measurement of the total drop in pressure and flow rate are taken into consideration. The 
purpose of this test is to establish the increase in the drop in pressure at the filter causing a 10  % 
reduction from the nominal air -flow rate under standard conditions. An acceptable minimum drop in 
pressur e which may cause a 10  % reduction from the nominal flow rate must be agreed upon by the 
manufacturer and user. For this drop in pressure, the flow rate indicated by the monitor may not differ 
by more than ±10  % from the conventional flow rate value.  
2.16   Influence of supply voltage on flow rate  
The flow rate may not change by more than 5  % if the supply voltage changes between +10  % and -
12 % of the nominal supply voltage.  
2.17   Influence of supply voltage frequency  
The flow rate may not change by more than 10  % if the supply voltage frequency changes from 47  Hz 
to 51  Hz. 
2.18   External leak  
This test is intended to determine the extent of an external leak, but not an internal leak around the 
filter holder or collection device. Air or gas leakage in the  device upstream of the flowmeter must be 
less than 5  % of the nominal flow rate.  
2.19   Ambient temperature  
The indicated specification must remain within the limits specified in Table  2 for the temperature 
range specified by the manufacturer. It must be noted that, for this type of device, the detection and 
sampling device can work under other climatic conditions than the evaluation device. Part of or the 
entire detection device can work at a temperature higher than that specified in Table  2. In such case , 
the applicable test must be agreed upon by the manufacturer and user.  
Table  2 – Ambient temperature  
Ambient temperature  Deviation from value under standard conditions  
+10 °C to +35  °C  
(median: +22  °C) 
−10 °C to +40  °C  
(median: +15  °C) 
–25 °C to +50  °C  
(median: +12  °C) ±10 %  
 
±20 %  
 
±50 %  General Measure No  0111 -OOP -C074 -16 
9 2.20   Relative air humidity  
The deviation caused by relative humidity up to 90  % at 35  °C must be less than 10  %. 
3   Technical requirements  
3.1   General requir ements  
The main requirement is the ability to measure a defined effluent level characterised by the volume 
activity and overall flow rate of the effluent.  
3.2   Monitor types  
3.2.1    General  
The types of gaseous effluent monitoring under consideration are monitors of radioactive aerosols, 
monitors of rare gases and monitors with specific differentiation of radionuclides.  
3.2.2    Aerosol monitors  
This device usually includes some kind of means of collection on a sampling medium, such as a static 
filter or m oving filter which is monitored by a suitable detection device. The selected detector must be 
suitable for the given type of radioactivity.  
3.3    Effluent sampling  
If the given type of measurement requires sampling, the effluent must be sampled at a repre sentative 
point of the effluent pipe in order to measure the actual leakage downstream of the input points and 
capture of radioactive substances.  
If, however, the required sensitivity is too low for reasonable measuring and if the activity comes from 
one o r more well -defined sources, it is a good idea to measure the effluent locally before further 
dilution with non -radioactive effluent. In this case, effluent from all sources of radioactive 
contamination must be monitored either collectively or individually . If flow capture devices are 
downstream of the effluent sampling point, the activity indicated by the monitor is not the activity of 
the actual leak and the efficiency of the capture device must be determined in order to estimate the 
actual leaks.  
In both  cases, two methods are possible.  
1. Measuring without withdrawing part of the flow relies on positioning the detector into the 
effluent flow or near the effluent flow. This has the advantage of simplicity and reduces 
problems associated with the representati veness of the sample. For a gas monitor, for instance, 
the detector may be positioned into the effluent flow; it must then be calibrated to the actual 
geometry for which it is used. Furthermore, it is necessary to prevent radioactive particles from 
gatheri ng on or near the detector, because this may interfere with the measurement.  
2. Measuring with a withdrawn part of the flow enables the detector to be positioned in an 
environment which is more suitable for measuring (as far as temperature, gamma background, 
etc. are concerned). For example, this enables particles and steam to be removed from the 
sample when gases are being measured. However, it is necessary to make sure the sample is 
representative.  
NOTE   The following characteristics should be taken into co nsideration:  
 optimal number and positioning of the sampling nozzles;  
 internal pipe diameter;  
 type of material used with specific regard to corrosion caused by chemical influences and electrostatic 
phenomena;  General Measure No  0111 -OOP -C074 -16 
10  surface treatment of internal surfaces;  
 radius o f curvature and direction of change;  
 length of pipe, inclination;  
 connection of the pipe, to external pipe, to monitor;  
 influence of harmful chemical products and water vapours.  
Problems may occur if the measured effluent has a high temperature and/or high  pressure. One 
solution is that the detector works under similar conditions. Another solution relies on preparing the 
sample at normal pressure and temperature (this is only possible when sampling part of the flow); the 
design of such an adjustment device is not the subject of this regulation, but the manufacturer and user 
must ensure that this device does not influence the representativeness of the sample.  
3.4   Activity collection  
If direct effluent flow measuring or withdrawal of a representative sample is not possible due to low 
volume activity of the effluent flow, then various methods of collecting activity may be considered 
prior to measurement. There are two approaches:  
 measuring activity during collection;  
 measuring after collection with a continuou sly repeating collection/measurement cycle.  
The most common such procedure is the concentration of air particles, vapours or gases on a suitable 
sampling medium. The medium may be in the form of a belt or volume absorption granules in a 
suitably packaged s ystem. After collection, the medium is exchanged and arranged so that one sample 
is measured and the next sample is collected.  
3.5   Measurement and indication characteristics  
3.5.1   Effective measuring range  
The effective measurement range must be suita ble for the given application.  
3.5.2    Measurement characteristics  
The manufacturer must indicate the device ’s decision level, detection limit and effective measurement 
range. These characteristics should be specified for specific radionuclides in consider ation of the level 
of background reference gamma radiation (0.2  Gy/h) and volume activity in the air (radon and its 
daughter products).  
3.5.3    Display  
It is desirable for the indicated value to be the actual volume activity of the effluent. This volume 
activity is usually given at Bq/m3 of the equivalent of the reference radionuclide or mixture thereof.  
3.6   Reliability  
The uptake time for the entire device must be less than 30  minutes.  
All devices must be designed to be reliable with a minimum of undete cted malfunctions wherever 
possible.  
The manufacturer must provide documentation on the expected average service life of critical 
components such as the air pump, detector, flow meter, etc.  
The manufacturer must specify the periodicity at which maintenance  must be repeated and fully 
describe all maintenance procedures. The requirements for this maintenance should be as small as 
possible.  
Alarms should be available for failures to indicate that the system has a fault, such as a power cut or 
component malfunc tion. General Measure No  0111 -OOP -C074 -16 
11 3.7   Characteristics of sample flow rate fraction from the effluent flow  
3.7.1   Pump  
If a pump is an inseparable part of any device, then the following requirements must be met:  
a) must be positioned downstream of the filter or activity measuring unit ; 
b) must be capable of uninterrupted operation between planned maintenance tasks. The frequency 
of maintenance tasks must be agreed upon by the manufacturer and user, but may not be more 
frequent than once every six months. The design must enable easy access  to the pump and 
replacement of its parts;  
c) must enable a constant flow rate to be maintained which is suitable for the given measurement 
method. If the method of measuring volume activity is sensitive to flow rate, the pump must be 
such that the flow rate  is only slightly influenced by a change in the drop in pressure in the 
circuit.  
3.7.2    Flow  rate control  
If the measurement method is sensitive to flow rate, a device to control the flow rate must be used 
which has a range of flow rate settings sufficien t to allow for changes in the intrinsic characteristics of 
the air pump and all filters used.  
3.7.3    Flow  rate measurement  
If the measurement method is sensitive to flow rate, a device to measure the flow rate must be used 
with an alarm warning of any exc essive change in flow rate. The flow rate must be measured 
downstream of the collection medium and upstream of the pump. The sampling flow rate must be 
expressed in SI units. The pressure and temperature at which the flow  rate meter is calibrated and at 
which the flow rate is expressed must be available. The necessary corrections must be made to the 
actual effluent conditions.  
3.7.4    Pressure control  
If the measurement method is sensitive to pressure within the measuring chamber, a device to measure 
the fl ow pressure must be used with an alarm warning of any excessive change in pressure in the 
measuring chamber.  
3.8   Alarms  
3.8.1   Types of alarm  
Alarms and indication elements must be suitable for the device ’s purpose and must be agreed upon by 
the manufac turer and the user.  
High -level alarms and malfunction alarms must provide separate local visual value on the monitor and 
must also have two sets of output contacts (which may be collective for all malfunction alarms) for the 
purposes of external alarms. Au dio alarms may also be provided.  
All alarm functions must have a means of testing to check the functionality of the alarm. In case of an 
adjustable alarm, inspection must be possible within the range of settings with an indication of the 
current alarm oper ation point.  
Alarm circuits must function either in a mode in which alarm conditions are maintained until specific 
zeroing via zeroing control or in an automatic zeroing mode in which the state of alarm disappears.  
3.8.2    High -level alarms  
A high -level ad justable alarm covering the entire effective measurement range must be provided.  General Measure No  0111 -OOP -C074 -16 
12 3.8.3    Malfunction alarms  
The following must be provided:  
 alarm indicating loss of detector signal;  
 alarm indicating loss of sampling in the circuit;  
 alarm indicating malfun ctions in the electronic system circuits.  
Wherever possible, alarms should indicate the source of the largest possible number of malfunctions 
and should have an automatic diagnostic system.  
There should be a separate value for each malfunction.  
3.9   Means  of indication  
Aside from the visual display of measured values, the device should have operating values for:  
 power supply on;  
 air pump on (if used);  
 high-voltage power supply to detector on (if used);  
 flow and/or level of coolant supply for detector (if u sed).  
If air flows through the device, then a suitable flow measurement value must be provided.  
An output enabling remote measurement and alarm value must be provided.  
3.10   Means of checking operation  
Means must be provided which enable the user to perio dically check that the device is operating 
satisfactorily, including calibration and linearity of measurement verification. These means should 
usually be installed so as to enable checks to be carried out from the control and evaluation unit.  
It must be po ssible to check the calibration of the device at two representative points in the 
measurement range.  
This check must be conducted by means of one or, if necessary, several suitable radioactive sources. 
Linearity of measurement may be checked electrically.  
3.11   Means of adjustment and maintenance  
All electronic devices must have a sufficient number of easily accessible testing points to simplify 
adjustments and fault localisation. All special instruments for maintenance and the necessary 
maintenance instru ctions must be supplied.  
The design of all devices must enable easy repair and maintenance.  
Information on automatic diagnostic elements should be accessible on the display.  
3.12   Detection device or sampling and detection device  
This device contains one or more radiation detectors and potentially one or more of the following sub -
devices and functional units:  
 sampling and suction pipe;  
 container or other apparatus for eliminating short -term disruptive gaseous radionuclides;  
 means of removing samples for la boratory analysis and for calibration tests with radioactive 
gases;  
 device to cool the detector;  
 sampling chamber;  General Measure No  0111 -OOP -C074 -16 
13  device to catch air particles;  
 device to move filter;  
 device to protect from ambient gamma radiation;  
 device to monitor and control air -flow rate; 
 air pump;  
 device to measure temperature, where appropriate.  
The detection device or sampling and detection device must be designed so as to minimise internal 
contamination and simplify decontamination when necessary. The outer surfaces should be spec ially 
treated to enable decontamination.  
If possible, the monitor should be designed so as to minimise the effects of mechanical impacts.  
Under certain circumstances, the effluent flow may contain an explosive mixture of gases. In this case, 
the device mus t be designed so as to prevent the possibility of the effluent being ignited by the 
instrument.  
The effluent may also contain harmful and corrosive chemical vapour and a special arrangement is 
needed to protect the measuring systems.  
If the detector is coo led from a local supply tank, it should not be necessary to fill up the tank more 
often than every eight days.  
3.13   Control and evaluation device  
The control and evaluation device primarily contains the following parts:  
 electrical control unit and power supply;  
 electronic measuring device;  
 measurement display unit;  
 warning signal and alarm units.  
The device may be connected to a radiation situation central display panel. In this case, it must be 
possible to install it in electronic frames of normal dimens ions.  
3.14   Ambient  background shielding or compensation devices  
These devices or procedures are used to reduce ambient background influence on the measurement. 
There are the following types:  
 shielding devices;  
 electronic devices;  
 software methods.  
These types may be integrated into the overall design of the system if necessary.  
The shielding should provide the same radiation attenuation in all directions from the detector ’s 
sensitive surface area with consideration of the detection device ’s construction m aterials and the 
detector ’s angle responses. The thickness of the shielding must be determined with respect to the 
detector ’s detection efficiency.  
If it is not possible to easily remove the device from the shielding, this shielding must be easily 
dismantl ed, and thus made up of constructional overlapping elements with a weight of 15  kg or less, 
unless agreed upon otherwise by the manufacturer and user.  
If electronic methods with the use of additional detectors are used to reduce gamma background, these 
detectors must be selected and positioned so as to achieve the best possible compensation in 
consideration of the gamma energy range and direction of radiation.  General Measure No  0111 -OOP -C074 -16 
14 3.15   Device noise level  
The device ’s noise level primarily comes from the sampling and detection  device and especially from 
the operation of the air pipe system and the arising vibrations.  
The manufacturer must select components and design the device so that the noise level will be 
minimal and in compliance with the type of environment for which the device is intended.  
3.16   Electromagnetic interference  
The measuring instruments may not be influenced by electrical and electromagnetic interference from 
the surroundings and must meet the requirements of separate legislation2.  The change in measuring 
instrument response may not exceed 1  % during the interference influence test. All necessary 
measures must be taken against the effects of electromagnetic interference and includes that which is 
received as well as emitted by the device.  
Severity level  3 is used for resistance.  
Severity class  A is used for radiation emission.  
3.17   Power supply  
The device should be designed for operation from single -phase alternating current voltage in one of 
the following categories:  
 Series  I: 230 V a.c.; 
 series  II: 100 V a.c.; 
 series  III: 120 V and/or 240  V a.c.  
 series  IV: 24 V d.c.  
The device may be designed for operation from a low -voltage backup source in case of a disturbance 
in power supply. In such cases, it is desirable for the device not to indicate a malfunction or  trigger an 
alarm as a result of switching over the power supply; and indication of this switch -over should be 
provided.  
Three -phase power supply may be used for air pump motors.  
3.18   Protection against unauthorised tampering  
The parts of the measuring i nstrument essential to its metrological characteristics must be designed to 
be secured in such a way as to provide proof of any unauthorised interference.  
If the measuring instrument ’s response can be adjusted by correcting the long -term change in 
respons e, correcting the influence of temperature and pressure on response or applying a corrective 
factor, then the measuring instrument must be designed so as to prevent unintentional change of any 
adjustment factor by the operator.  
Control switches and potent iometers must either be inside the measuring instrument and inaccessible 
from the outside without using tools, or be clearly marked and fitted with a scale so that they can be 
precisely adjusted according to the resolution of the measuring instrument and t hen locked in order for 
the settings not to be changed accidentally. Correction factors and calibration coefficients stored 
digitally may not be changed unless the operator enters the security code (or password) or changes the 
position of the blocked or in accessible switch.  
                                                      
2  Government Regulation No  117/2016 on product conformity assessment regarding electromagnetic 
compatibility when s upplied on the market  General Measure No  0111 -OOP -C074 -16 
15 3.19   Safety  
The measuring instrument must be safe in accordance with the basic principles of safety of ionising 
radiation installations and the requirements of relevant technical regulations under the conditions of 
normal use for the i ntended purposes.  
4   Measuring instrument markings  
4.1   Markings on the measuring instrument  
The following information must be provided on each part of the measuring instrument, which may 
consist of two functionally separate parts:  
a) Manufacturer identific ation;  
b) Designation of the type of measuring instrument;  
c) serial number of the detector(s), evaluation unit of the measuring instrument, pump, flow meter;  
d) type-approval mark;  
e) information on the safety of the ionising radiation measuring instrument.  
All label s and inscriptions must be legible, durable, unambiguous and unalterable.  
4.2   Placement of the official mark  
The placement of official marks on the detection part and the evaluation unit is specified in the type -
approval certificate.  
Where possible, mar ks are to be placed on the front panel of the display unit so that they do not cover 
any of the data on the measuring instrument.  
5   Type -approval of measuring instrument  
5.1   General  
The measuring instrument type -approval process includes the following tests:  
a) External inspection;  
b) instrument accuracy;  
c) system linearity;  
d) change in detection efficiency as function of beta radiation energy (beta aerosol monitors);  
e) response to radioactive gases;  
f) response to daughter products 222Ra; 
g) response to ambient gamma ra diation;  
h) overloading;  
i) detection and evaluation device uptake time;  
j) statistical fluctuation;  
k) stability of values on detection and evaluation device;  
l) flow rate stability;  
m) influence of pressure loss on the filter;  
n) influence of supply voltage on flow rate;  
o) influence of supply voltage frequency;  
p) external leak;  
q) influence of ambient temperature;  General Measure No  0111 -OOP -C074 -16 
16 r) influence of relative air humidity;  
s) electromagnetic compatibility.  
5.2   External inspection  
The external inspection assesses  
a) the completeness of the prescribed technical documentation, including the operating 
instructions;  
b) the conformity of the metrological and technical characteristics specified by the manufacturer in 
the documentation with the requirements under this regulation as referred to in Chapters  2 and 
3; 
c) the com pleteness and status of the functional units of the measuring instrument according to the 
prescribed technical documentation;  
d) the software version of the measuring instrument with the version specified by the 
manufacturer.  
5.3   Functional tests  
5.3.1   In strument accuracy  
The device operates under standard test conditions and is set according to the manufacturer ’s 
instructions without reference radiation being present. The background value is recorded. Then the 
device is irradiated with a suitable referenc e source with sufficient activity to provide a value 
approximately in the middle of the scale or several increments of 10 above the lowest scale or 
increment of 10. The specification indicated is recorded and the value Rref is quantified.  
The measured val ue must not exceed the permitted change limits specified in Article  2.3. 
5.3.2    System linearity  
The test is conducted with a set of sources of the same radionuclide and geometric characteristics. 
However, standard preparation of the test sources used in the required tests must be such that the 
absolute conventional uncertainty of the activity value ( sa) of each source is better than 10  % (k = 2) 
and the relative uncertainty of conventional activity value ( sr) between the sources of the given test set 
is better than 5  % (k = 2).  
The tests may be carried out two ways:  
a) with gaseous or solid radioactive sources;  
b) with an electrical signal supply.  
The tests are conducted at a single point on each scale for devices with a linear scale and on each 
increme nt of 10 on the effective measurement range for devices with a numerical or logarithmic 
display approximately at 25  % of the most sensitive range or increment of 10, at 50  % of the 
maximum moderate range or increments of ten and 75  % of the maximum value. At least three of 
these tests must be carried out with the help of a radioactive source, while two are on threshold values. 
If electrical signals are used, they must be used at all ranges or increments of 10 (in addition to 
radionuclide sources).  
The measu red value must not exceed the permitted change limits specified in Article  2.4. 
5.3.3   Change in detection efficiency as function of beta radiation energy (beta aerosol monitors)  
The tests are conducted with at least three sources of beta radiation, the m aximum energies of which 
are divided as follows:  
 for one source ≤ 0.4 MeV;  
 for one source between 0.4  MeV and 1  MeV;  General Measure No  0111 -OOP -C074 -16 
17  for one source ≥ 1 MeV.  
The sources of beta radiation used may be selected from the list on Table  3. 
Table  3 – List of radionuclide suitable for tests with change of beta energy  
Radionuclide  Half -life Maximum beta radiation energy  
(MeV)  
63Ni 
14C 
203Hg 
147Pm 
45Ca 
60Co 
137Cs 
 
185W 
204Tl 
36Cl 
198Au 
 
89Sr 
32P 
90Sr+90Y 96 y 
5 730 y 
46.6 d 
2.6234  y 
163 d 
5.271  y 
30.0 y 
 
75.1 d 
3.779  y 
3.01 × 105 y 
2.696  d 
 
50.5 d 
14.29  d 
29.12  y 0.0659  
0.1565  
0.2122  
0.2247  
0.2569 
0.3179  
0.51155 (94.6  %) 
1.1732 (5.4  %) 
0.4324  
0.7634 (97.4  %) 
0.70955 (98.1  %) 
0.28241 (1.30  %) 
0.9607 (98.7  %) 
1.4913  
1.7104  
0.545  
2.2839  
 
All sources used must have sufficient activity to reach the indicated specification with a standard 
deviation o f less than 1  %. 
Tests of change in detection efficiency with alpha radiation energy are not required, since the detection 
efficiency usually does not depend on energy.  
If mixed alpha -beta activities are used to measure beta or alpha activities in the effl uent, then the 
measurement may be influenced by a second non -specific radiation. The limit of detection efficiency 
for non -specific radiation must be less than 2  % for sources of beta radiation in the alpha channel and 
25 % for sources of alpha radiation m easured in the beta channel.  
Detection efficiency ( ) must be expressed by the frequency of impulses in relation to the surface 
emission input of the respective source and is as follows:  
 emiseplošnéimpulsů četnost
příkon
  (9) 
četnost impulsů  frequency of impulses  
příkon plošné emise  surface emission input  
The given device ’s detection efficiency must be determined for the second radiation with the help of a 
source of the second radiation (an alpha radiation source for a beta monitor, a beta radiation source for 
an alpha monitor). The sources of radiation need not necessarily be sources with reference energies, 
but they should be sources which probably cause interference: such as 241Am for alpha radiation and 
90Sr + 90Y for beta radiation.  
The efficiency stated in th e same units as ref must be:  
 ≤ 0.02 ref  for beta radiation in the alpha channel  General Measure No  0111 -OOP -C074 -16 
18  ≤ 0.25 ref  for alpha radiation in the beta channel  
The measured value must not exceed the permitted change limits specified in Article  2.5. 
5.3.4    Response to radioactive gases  
The manufacturer must  specify the response to the respective radioactive gases present in the sample 
of air or carrier gas.  
Two methods may be used.  
1. A known volume activity of rare gas (such as 133Xe or 85Kr) is supplied to the monitor for the 
amount of time necessary to reach  an equilibrium. A reading corresponding to the equilibrium 
value is recorded. The result is expressed as the ratio of the indicated value to the volume 
activity of the test gas.  
2. The supply air pipe is connected to the output air pipe and the total volume of air in the pipe is 
measured (e.g. the supply air pipe is connected to a known volume under pressure and the 
change in pressure at equilibrium is recorded). A small volume (1  % of the volume of the air 
pipe) of gas such as 133Xe or 85Kr of a known activi ty is fed into the system. The aerosol monitor 
is then operated normally. A response corresponding to equilibrium is recorded and the highest 
value is reached. The result is expressed as the ratio of the indicated value to the volume activity 
of the gas be ing tested.  
The measured value must not exceed the permitted change limits specified in Article  2.6. 
5.3.5    Response to daughter products 222Ra  
Since the relationship between response to daughter products of radon and the decision level and both 
paramete rs usually depends on the given use in operation, the response to daughter products of radon 
and the decision level must be agreed upon by the manufacturer and the user.  
The manufacturer must specify the decision level and the maximum indication level whe n a detector 
with elements for radon compensation is exposed to the effect of natural radioactive aerosols with a 
sudden change in volume activity from reference background without the presence of radon and its 
daughter products to avRa= 1 kBq.m-3 from 222Ra. The manufacturer must specify the method used to 
reduce the influence of daughter products of radon on the monitor ’s response and a test must be 
conducted to establish the effectiveness of this method. Natural and artificial radioactive aerosols can 
be distinguished using special algorithms by processing the primary frequency of impulses measured 
by the detector at the filter or by another technique intended to separate the signal of the artificial 
aerosols from the natural ones and thus suppress their influence on the measurement result as much as 
possible. The quantity characterising this process is called the radon compensation coefficient kRa and 
is defined as:  
kRa = 
Ra,D,D
LL 0   (10) 
in which LD,0 is the detector ’s detection limit determi ned without the presence of radon and its 
daughter products and LD,Ra is the detector ’s detection limit at avRa = 1 kBq.m-3 
The device must work under standard test conditions without the presence of a radioactive source and 
the indicated background specif ication is determined. Depending on its design, the detector is then 
exposed to the influence of 222Ra, air of a known volume activity is fed through the detector, or the 
detector is placed in an area with a known volume activity of 222Ra. The method of in fluencing the 
222Ra detector must be in accordance with the manufacturer ’s specifications. After the onset of 
irradiation, the values are recorded at intervals of one minute and recording is continued until the 
device gives a stable value. Once a stable st ate has been reached, at least 10 readouts are carried out. 
The detection limit is determined based on the final readouts and the radon compensation coefficient. 
This must be in accordance with the manufacturer ’s specifications.  General Measure No  0111 -OOP -C074 -16 
19 The detector is then irrad iated in several different volume activities as agreed upon by the 
manufacturer and user. If the evaluation device can be programmed with a compensation factor for 
222Ra, then the factor must not be changed during this test. The readout on the evaluation d evice may 
not exceed two times the value specified by the manufacturer for avRa = 1 kBq.m-3 for all volume 
activities of 222Ra. 
The measured value must not exceed the permitted change limits specified in Article  2.7. 
5.3.6    Response to ambient gamma radia tion 
Since the relationship between response to ambient gamma radiation and the decision level and both 
parameters usually depends on the given use in operation, the response to gamma radiation and the 
decision level must be agreed upon by the manufacturer  and the user. The manufacturer must specify 
the decision level and the maximum indication level when a detector with elements for protection 
from ambient gamma radiation is irradiated in the position specified by the manufacturer with a 
sudden change in i nput air kerma from the reference background input air kerma to 10 Gy/h for 
137Cs. The response to irradiation with gamma radiation at any orientation and any gamma radiation 
energy up to 1.3  MeV (60Co) may not exceed two times the value of the decision l evel.  
The device must work under standard test conditions without the presence of a radioactive source and 
the indicated background specification is determined. The source of 137Cs is then positioned in relation 
to the detector so that the distance between  the source and the detector is at least 2  metres and the 
conventional air kerma input value at the detector ’s location (as if the detector were not present) is 10 
Gy/h  ± 10 %. The reference orientation of the detector must be in accordance with the 
manuf acturer ’s specifications. After the onset of irradiation, the values are recorded at intervals of one 
minute and recording is continued until the device gives stable values. Once a stable state has been 
reached, at least 10 readouts are carried out. The de cision level is calculated based on the final 
readings. This decision level must be in accordance with the manufacturer ’s specifications. The 
maximum readout on the evaluation device may not exceed the value specified by the manufacturer. 
The detector is t hen irradiated in several source -detector geometries as agreed upon by the 
manufacturer and user. If the evaluation device can be programmed with a compensation factor for 
gamma radiation, then the factor must not be changed during this test. The readout o n the evaluation 
device in all directions may not exceed two times the value specified by the manufacturer for the 
reference direction.  
The above -mentioned test is repeated for the source -detector reference direction with the use of 
alternative sources of gamma radiation as agreed upon by manufacturer and user, including a source of 
60Co. If the evaluation device can be programmed with a compensation factor for gamma radiation, 
then the factor must not be changed during this test. The readout on the evaluat ion device may not 
exceed two times the value specified by the manufacturer for 137Cs. 
The measured value must not exceed the permitted change limits specified in Article  2.9. 
5.3.7    Overload test  
Unless the manufacturer and user agree otherwise, the devi ce must indicate a value off the scale at its 
upper end or indicate overloading when irradiated with a source with an activity (or surface emission 
input) 10 times greater than that corresponding to the maximum measurement range, and then function 
normally  after the overloading is eliminated.  
a) The detection device is exposed to a source of radiation of an activity which provides a value of 
approximately 50  % of the first increment of 10 on the measurement range and the value 
readout is recorded.  
b) The detecti on device is exposed to a source of radiation with an activity 10 times greater than 
that which corresponds to the maximum measurable value. The radiation is maintained for at 
least 10  minutes and it is verified that the instrument continuously shows a val ue off the scale at 
its uppermost end.  General Measure No  0111 -OOP -C074 -16 
20 c) The source of radiation is removed and, after a period of time agreed upon by the manufacturer 
and user (usually less than 1  hour), the detection device is irradiated under the same conditions 
as in a). The values rea d out may not differ from the original value by more than 10  %. 
5.3.8    Detection and evaluation device uptake time  
When irradiated with a radiation source, the device must indicate a value which will not vary by more 
than ±10  % from the value obtained und er normal conditions in a period of up to 30  minutes after 
being switched on.  
The device must be disconnected from the mains for at least 1  hour prior to this test. A radiation 
source is used which provides an value at approximately one third to one half of the maximum range. 
The detection and evaluation device are turned on. The values indicated are recorded every 5  minutes 
for 1 hour. Ten hours after being turned on, a sufficient number of readouts is carried out in 
accordance with Chapter  25 and the mea n value is used as a ‘final value ’ of the indications. A graph is 
drawn of the activity value indicated at the time and the half -life is adjusted if necessary. The 
difference between the ‘final value ’ and the value read out on the curve for 30  minutes must  lie within 
the specified limits.  
NOTE   If the level of activity is very low, less than 10 times the decision level, it may happen that the device 
does not specify the indicated value required during the uptake time. This is caused by statistical deviatio ns at 
the low frequencies of impulses measured.  
5.3.9    Statistical fluctuation  
In light of the statistical nature of radiation, the values read out may fluctuate around the mean value. 
The coefficient of variation of the activity value caused by the stati stical fluctuations must be less than 
10 % for values exceeding the first increment of 10 on the effective measurement range.  
A radioactive source is used which provides an indicated value between 10 and 20 times the decision 
level. At least 10 readouts ar e conducted at suitable intervals of time in order to obtain independent 
values. The mean value and coefficient of variation of all readouts made are calculated. The 
coefficient of variation must be within the required limits.  
The measured value must not e xceed the permitted change limits specified in Article  2.12.  
5.3.10    Stability of values on detection and evaluation device  
The specification indicated with the given radiation source after 30  minutes of device operation may 
not change by more than 10  % for the next 100 hours.  
A radioactive source is used which provides an indicated value between 10 and 20 times the decision 
level. A sufficient number of readouts are carried out after 30  minutes, additional readouts are 
conducted after 10  hours and 100  hours without making any adjustments to the device and without 
changing any conditions. The mean values of the readouts must lie within the specified limits for all 
times.  
If necessary, the readouts must be corrected to half -life. 
The measured value must not exceed the permitted change limits specified in Article  2.13.  
5.3.11    Flow  rate stability  
The purpose of this test is to establish the nominal flow rate of sampling and the stability of sampling 
under standard test conditions with a loss of pressure cause d only by the air circuit and input or 
sampling filter (clean filter). The manufacturer must specify the nominal flow rate for the filter type 
used. After the standard sampling device uptake time (30  minutes), the indicated sampling flow rate 
may not diffe r by more than ±10  % from the conventional flow rate value and the sampling flow rate 
may not change by more than 10  % for the next 100 hours.  
This test is conducted in dust -free air in order to prevent any kind of change to the collection device ’s 
drop in  pressure during the test. For that reason, a HEPA filter with a very low drop in pressure is General Measure No  0111 -OOP -C074 -16 
21 placed upstream of the air circuit. For this test, a flow meter calibrated under measurement conditions 
and having an uncertainty better than 3  % (k = 2) is insta lled at the input to the air circuit. The device 
is turned on and the flow rate is measured after 30  minutes, 5  hours, 20 hours and 100 hours of 
operation. The readouts must be in accordance with the requirements.  
The measured value must not exceed the per mitted change limits specified in Article  2.14.  
5.3.12    Influence of pressure loss on the filter  
Because the influence of the filter properties and the degree of blockage may vary from test to test, 
only the measurement of the total drop in pressure and f low rate are taken into consideration. The 
purpose of this test is to establish the increase in the drop in pressure at the filter causing a 10  % 
reduction from the nominal air -flow rate under normal conditions. An acceptable minimum drop in 
pressure which  may cause a 10  % reduction from the nominal flow rate must be agreed upon by the 
manufacturer and user. For this drop in pressure, the flow rate indicated by the monitor may not differ 
by more than ±10  % from the conventional flow rate value.  
For this tes t, the monitor must be equipped with a clean collection medium. The flow meter is inserted 
before the monitor and adjustable limiter (such as a valve) between the flow meter and monitor input. 
A calibrated pressure sensor (or differential pressure gauge, e tc. in the case of a tube) is positioned 
after the collection medium at the point determined by the manufacturer in order to measure the drop 
in pressure in the monitor caused by the air flow. The nominal flow rate is measured at the nominal 
drop in pressu re at the collection medium, then the adjustable limiter shall be set to achieve a mean 
flow rate value of 10  % below the nominal flow rate under standard test conditions. The conventional 
value of the sampling flow rate is measured under these conditions.  
The measured drop in pressure and flow rate must meet the requirements under these conditions.  
The measured value must not exceed the permitted change limits specified in Article  2.15.  
5.3.13   Influence of supply voltage on flow rate  
The supply voltage c hanges between +10  % and −12 % of the nominal supply voltage.  
This test is conducted in dust -free air in order to prevent any kind of change to the collection device ’s 
drop in pressure during the test. For that reason, a HEPA filter with a very low drop in  pressure is 
placed upstream of the air circuit. For this test, a flow meter calibrated under measurement conditions 
and having an uncertainty better than 3  % (k = 2) is installed at the input to the air circuit. The device 
is switched on and the flow rate  is measured at stable voltage, and a record is made of the flow rate. 
After that, the supply voltage is changed in a defined range of 88  % UN to 110  % UN and the flow 
rate is measured at the same time.  
The measured value must not exceed the permitted cha nge limits specified in Article  2.16.  
5.3.14    Influence of supply voltage frequency  
The supply voltage frequency changes from 47  Hz to 51  Hz. 
During this test, the sampling and detection device is connected to the nominal voltage supply and 
frequency, wh ich changes from 47  Hz to 51  Hz (alternative values are 57  Hz to 61  Hz). The test is 
conducted in dust -free air in order to prevent any kind of change to the collection device ’s drop in 
pressure during the test. For that reason, a HEPA filter with a very l ow drop in pressure is placed 
upstream of the air circuit. For this test, a flow meter calibrated under measurement conditions and 
having an uncertainty better than 3  % (k = 2) is installed at the input to the air circuit. The flow rate is 
recorded at the nominal frequency and at specified limit frequencies.  
The measured value must not exceed the permitted change limits specified in Article  2.17.  General Measure No  0111 -OOP -C074 -16 
22 5.3.15    External leak  
This test is intended to determine the extent of an external leak, but not an internal l eak around the 
filter holder or collection device.  
The size of the leak is measured with two volume gauges or flow rate meters, which must mutually be 
calibrated more precisely than 1  %. The filter holder is fitted with a clean filter or other capture dev ice. 
One meter is placed upstream of the device and the second in the direction of flow downstream of the 
filter or other capture device and immediately before the flow rate meter installed in the device. A 
series of 10 of the following measurements is car ried out at suitable intervals of time (even after heavy 
fouling). The mean values of flow rates measured upstream and downstream may not differ by more 
than 5  % during the normal sampling period. A correction of the air pressure differences is carried out  
if necessary.  
The measured value must not exceed the permitted change limits specified in Article  2.18.  
5.3.16   Ambient temperature  
It must be noted that, for this type of device, the detection and sampling device can work under other 
climatic conditions  than the evaluation device. Part of or the entire detection device can work at a 
higher temperature.  
The detection device is irradiated with a suitable test source so that the nominal value is known under 
standard test conditions. This test is usually con ducted in an environmental chamber. Usually, it is not 
necessary to regulate the air humidity in the chamber if the device is not particularly sensitive to 
changes in humidity. The temperature is maintained at both of its limit values of the agreed 
tempera ture range for a period of at least 24  hours. The indicated specification is measured over the 
last 30  minutes of this interval and must be in within the applicable limits. In addition, the indicated 
specification is measured at the mean of the temperature  range specified in Table  2. If the readout at 
this mean temperature is not within limits of ±10  % with respect to the monitor ’s readout at the 
reference temperature, the manufacturer must specify the difference at this point.  
The measured value must not e xceed the permitted change limits specified in Article  2.19.  
5.3.17    Relative air humidity  
It must be noted that, for this type of device, the detection and sampling device can work under other 
climatic conditions than the evaluation device. Part of or th e entire detection device can work at a 
higher relative humidity value.  
The detection device is irradiated with a suitable test source so that the nominal value is known under 
standard test conditions. The test can be carried out at a temperature of +35  °C and a relative air 
humidity of 90  %; the permissible deviation of ±10  % from the specification is in addition to the 
permissible deviation caused by the temperature itself.  
The measured value must not exceed the permitted change limits specified in Articl e 2.20.  
5.4   Electromagnetic compatibility (EMC) test  
EMC tests are conducted with an aerosol monitor connected according to the manufacturer ’s 
specification. These tests must demonstrate that the aerosol monitor is in conformity with the 
requirements of the applicable separate legislation2. 
5.4.1   Immunity to electrostatic discharge  
Immunity to electrostatic discharge is tested with the instrument switched on, with a contact discharge 
of 6 kV and an air discharge of 8  kV. The discharges are applied to th e conductive surfaces and 
junction plates.  General Measure No  0111 -OOP -C074 -16 
23 After this test, the measured deviation may not exceed the limits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.2    Immunity to high -frequency electromagnetic fields  
Immunity to a radiated high -frequency field shall be tested with the instrument switched on, in the 
frequency range of 80  MHz to 3  000 MHz at a field intensity of 10  V/m. Amplitude modulation 80  % 
AM/1  kHz sine.  
After this test, the measured deviation may not excee d the limits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.3    Immunity to rapid transient phenomena  
Immunity to repeated rapid electrical transient phenomena/burst impulses shall be tested with the 
instrument switched  on. A test voltage of ±0.5  kV, ±1  kV and ±2  kV is applied with a coupling circuit 
to the power, earth and signal inputs/outputs.  
After this test, the measured deviation may not exceed the limits specified in Article  2.3 during a 
subsequent test of the ins trument ’s accuracy.  
5.4.4    Resistance to surges  
Resistance to surges is tested by applying a test voltage of ±0.5  kV, ±1  kV and ±2  kV between the 
power conductors.  
After this test, the measured deviation may not exceed the limits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.5    Immunity to disturbances from high power lines induced by high -frequency fields  
Immunity to disturbances from high power lines induced by high -frequency fields is tested with the 
instrument sw itched on in a frequency band of 150  kHz to 80  MHz. Amplitude modulation 80  % 
AM/1  kHz, voltage level 10  V. 
After this test, the measured deviation may not exceed the limits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.6   Immunity to disturbances induced by damped oscillatory waves  
Immunity to disturbances induced by damped oscillatory waves is tested with the instrument switched 
on by applying a damped oscillatory wave to the power, signal and control inputs/outputs  of the 
monitor. The test level is defined as the voltage of the first peak (maximum or minimum) at the test 
shape of the wave and is asymmetrical 2  kV, symmetrical 1  kV for a slow damped oscillatory wave 
100 kHz and 1  MHz, for rapid damped oscillatory wav e 3 MHz, 10  MHz or 30  MHz and is 2  kV 
asymmetrical.  
After this test, the measured deviation may not exceed the limits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.7 Immunity to voltage dips, short interruptions and vo ltage variations  
Immunity to voltage dips, short interruptions and voltage variations is tested with the instrument 
switched on by applying a voltage dip to level 0  % Ut for a period of 10  ms.  
After this test, the measured deviation may not exceed the li mits specified in Article  2.3 during a 
subsequent test of the instrument ’s accuracy.  
5.4.8    Measuring disruptive terminal voltage  
The monitor tested must comply with the interference limits specified in Tables  4 and 5. The test is 
conducted with the devi ce switched on by measuring the disruptive terminal voltage at the power, General Measure No  0111 -OOP -C074 -16 
24 signal and control inputs/outputs of the monitor. If the value of the measuring receiver fluctuates near 
a limit, then the value must be observed for at least 15  seconds at each meas urement frequency. The 
highest value is measured, with the exception of random brief extreme values, which are ignored.  
The limits for disruptive terminal voltage at the mains terminals are specified in Table  4. 
Table 4 – Limits for conducted disturbances  at mains terminals  
Frequency range  
(MHz)  dB limits (µV)  
Quasi -peak  Average  
0.15 to 0.50  79 66 
0.50 to 30  73 60 
NOTE   For frequencies at the boundary of a band, the lower limit shall apply.  
The limits for disruptive terminal voltage at the signal in puts/outputs are specified in Table  5. 
Table  5 – Limits for disturbances from power lines on signal inputs/outputs  
Frequency range  
(MHz)  dB voltage limits (µV)  dB current limits (µA)  
Quasi -peak  Average  Quasi -peak  Average  
0.15 to 0.50  97 to 87  84 to 74  53 to 43  40 to 30  
0.50 to 30  87 74 43 30 
NOTE   For frequencies at the boundary of a band, the lower limit shall apply.  
5.4.9   Measuring the disruptive electromagnetic field (radiated high -frequency interference)  
The monitor tested must comply with the interference limits specified in Table  6. The test is conducted 
with the device switched on by measuring the radiated electromagnetic field at a distance of 10  metres. 
If the value of the measuring receiver fluctuates near a limit, then the value must be o bserved for at 
least 15  seconds at each measurement frequency. The highest value is measured, with the exception of 
random brief extreme values, which are ignored.  
Table  6 – Limits of conducted radiation interference at a measurement range of 10  m 
Frequen cy range  
MHz  Quasi -peak limits  
dB (µV/m)  
30 to 230  40 
230 to 1  000 47 
NOTE   For frequencies at the boundary of a band, the lower limit shall apply.  
6   Initial verification  
6.1   General  
During initial verification, the following tests are performed:  
a) Visual inspection;  
b) instrument accuracy;  General Measure No  0111 -OOP -C074 -16 
25 c) system linearity;  
d) change in detection efficiency as function of beta radiation energy (beta aerosol monitors);  
e) response to ambient gamma radiation;  
f) overloading;  
g) statistical fluctuation;  
h) stability of values on detect ion and evaluation device;  
i) flow rate stability;  
j) influence of ambient temperature.  
6.2   Visual inspection  
The inspection is conducted pursuant to Article  5.2. 
6.3   Functional tests  
6.3.1    Instrument accuracy test  
The test is conducted pursuant to Article  5.3.1.  
6.3.2   Instrument linearity test  
The test is conducted pursuant to Article  5.3.2.  
6.3.3   Test of change in detection efficiency as function of beta radiation energy  
The test is conducted pursuant to Article  5.3.3.  
6.3.4   Response to ambient gam ma radiation  
The test is conducted pursuant to Article  5.3.5.  
6.3.5    Overload test  
The test is conducted pursuant to Article  5.3.7.  
6.3.6    Statistical fluctuation test  
The test is conducted pursuant to Article  5.3.9.  
6.3.7   Long -term stability test  
The test is conducted pursuant to Article  5.3.10.  
6.3.8   Long -term flow rate stability test  
The test is conducted pursuant to Article  5.3.11.  
6.3.9   Test of ambient temperature influence  
The test is conducted pursuant to Article  5.3.16.  
7   Subsequent verif ication  
7.1   General  
During initial verification, the following tests are performed:  
a) Visual inspection;  
b) instrument accuracy;  General Measure No  0111 -OOP -C074 -16 
26 c) system linearity;  
d) overloading;  
e) stability of values on detection and evaluation device;  
f) flow rate stability.  
7.2   Visual inspectio n 
The inspection is conducted pursuant to Article  5.2. 
7.3   Functionality tests  
7.3.1    Instrument accuracy test  
The test is conducted pursuant to Article  5.3.1.  
7.3.2   Instrument linearity test  
The test is conducted pursuant to Article  5.3.2.  
7.3.3    Overload test  
The test is conducted pursuant to Article  5.3.7.  
7.3.4   Long -term stability test  
The test is conducted pursuant to Article  5.3.10.  
7.3.5   Long -term flow rate stability test  
The test is conducted pursuant to Article  5.3.11.  
8   Measuring instr ument verification  
When examining measuring instruments pursuant to §  11a of the Metrology Act at the request of a 
person who may be affected by an incorrect measurement, please proceed pursuant to Chapter  7. The 
maximum permissible error used is double th e maximum permissible errors pursuant to Chapter 7.  
9   Notified standards  
For the purposes of specifying the metrological and technical requirements for measuring instruments 
and specifying the testing methods for their type -approval and verification aris ing from this general 
measure, the CMI shall provide notification of the Czech technical standards, other technical standards 
or technical documents of international or foreign organisations, or other technical documents 
containing more detailed technical requirements (hereinafter referred to as ‘notified standards ’). The 
CMI shall publish a list of these notified standards attached to the relevant measures, together with the 
general measure, in a manner accessible to the public (on www.cmi.cz ). 
Compliance with notified standards or parts thereof is considered, to the extent and under the 
conditions stipulated by a general measure, to be compliance with the requirements stipulated by this 
measure to which these standards or parts thereof apply.  
Compliance with notified standards is one way of demonstrating compliance with the requirements. 
These requirements may also be met by using another technical solution guaranteeing an equivalent or 
higher level of protection of legitim ate interests.  General Measure No  0111 -OOP -C074 -16 
27 II. 
G R O U N D S 
The CMI issues, pursuant to §  14(1)(j) of the Metrology Act, for the implementation of §  6(2), §  9(1) 
and (9) as well as §  11a(3) of the Metrology Act, this measure of a general nature, stipulating 
metrological and technica l requirements for specified measuring devices and test methods for type -
approval for verification of the following specified measuring devices – ‘measuring instruments used 
to monitor activity limits and concentration of effluents from nuclear facilities,  nuclear raw material 
mining or processing facilities, radioactive waste processing plants and from the processing or 
application of radioactive materials, and also used to determine environmental radiation exposure due 
to effluents – measuring instruments for the continuous monitoring of radioactive aerosols including 
transuranic aerosols in gaseous effluents from nuclear facilities .’  
Decree  No 345/2002 laying down measurement instruments for mandatory validation and 
measurement instr uments subject to type -approval, as amended, classifies the measuring instruments 
under item  8.1 in the Annex to the Second List of Specified Measurement Instruments of the specified 
type as measurement instruments subject to type -approval and mandatory va lidation.  
This legislation ( general measure) 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. 
I N S T R U C T I O N S 
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 general draft measure. With regard to 
the provisions of § 172(4) APC, comments are to be submitted in writi ng. 
Pursuant to the provisions of § 174(1) APC, in conjunction with the provisions of § 37(1) APC, it must 
be clearly stated who is submitting the comments, which general measure the comments concern, how 
the draft contradicts legislation or how the genera l measure is inaccurate. The comments must also 
contain the signature of the person making the comments.  
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.  
 
 
 
 ................................ .......................   
RNDr. Pavel Klenovský  
Director -General  
 
 
Person responsible for accuracy: Mgr. Tomáš Hendrych  
 General Measure No  0111 -OOP -C074 -16 
28 Posted on:  
Signature of the authorised person conf irming posting:  ................................ ..............    
 
Removed on:  
Signature of the authorised person confirming removal:  ................................ ............