Czech Metrology Institute  
Okružní 31, 638 00  Brno  
 
1. ------IND- 2018 0579 CZ - EN- ------ 20181213 --- --- PROJET 
Executive summary for the EC (not part of this legislation)  
'‘Measuring instruments used to monitor activity limits and volume activity of effluents from nuclear 
facilities, nuclear raw materia l 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 iodine in gaseous effluents from nuclear facilities ’ may be placed on the 
market and put into use in the Czech Republic as specified measuring instruments  pursuant to 
Act No 505/1990 on metrology, as amended. In accordance with th is Act, specified measuring 
instruments are measuring instruments whose type is specified in the 'List of Specified Measuring 
Device Types' (Decree  No 345/2002) and which are specified (by the manufacturer or importer) for 
measurements relevant to the prot ection of public interest in fields of consumer protection, contractual 
relations, stipulation of sanctions, fees, tariffs and duties, health protection, environmental protection, 
occupational safety or protection of other public interests protected by sep arate legislation.  This is the 
same purpose of use by means of which specified products are defined – measuring instruments and 
scales with non -automatic operation pursuant 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 metrology.  
The subject of this notified regulation is to lay down metrological and technical req uirements for 
specified measuring instruments of the above -mentioned type. This regulation also stipulates tests for 
type approval and verification of measuring instruments of the above -mentioned type.  
(End of executive summary.)  
 
Author: Mgr. Tomáš Hendry ch 
Telephone: +420 545 555 414  
 
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 t esting 
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 provisions 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 on supporting 
documents, issues th e following:  
 General Measure  No 0111 -OOP -C073 -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 -C073 -16 
laying down the metrological and technical requirements for legally controlled measuring 
instruments, including testing methods for verification of the following legally cont rolled 
measuring instruments:  
 
‘Measuring instruments used to monitor activity limits and volume activity of effluents 
from nuclear facilities, nuclear raw material mining or processing facilities, 
radioactive waste processing plants and from the processin g or application of 
radioactive materials, and also used to determine environmental radiation exposure 
due to effluents – measuring instruments for the continuous monitoring of radioactive 
iodine in gaseous effluents from nuclear facilities ’ 
 
1   Basic def initions  
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 advantageously be connected to two component devices, which may be connected or 
separated according to monitoring and operational requirements  
1.2 
iodine monitor  
device intended for continuous or seque ntial measurement of volume activity of radioactive iodine in 
gaseous effluents released into the environment  
1.3 
radioactive iodine  
radioisotopes of iodine 131I, 125I and 129I 
1.4 
detection device  
encompasses one or more radiation detectors and associate d 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 Legal Metrol ogy (VIML) are part of the technical harmonisation 
compendium ‘Terminology in the field of metrology ’, which is publicly available at www.unmz.cz.  General Measure  No 0111 -OOP -C073 -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
iix x
nx xsV
12) (
11 1
  (1) 
1.7 
detection limit LD 
measured va lue 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 L D: 
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 the 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 quant ity 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 i n 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 indication and the signal at the decision level  General Measure  No 0111 -OOP -C073 -16 
4 1.13  
indication error  
difference between  the indicated value of the quantity  and conventionally correct value of this 
quantity c at the measurement point  
 =  – c (4) 
1.14  
relative fundamental error  
the relative error of the indication ei of a part of the device or system with respect to the given quantity 
at specified reference radiation and under specified reference conditions, expressed as:  
 
cc
ie
  (5) 
in which    ......  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 ra tio of volume activity accessible to measurement on the capture medium and 
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 a 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  
the air circuit monitor efficiency describe s the loss of activity on the walls 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
  (6) 
in which  A ....  is the volume activity value indicated by the test device or system,  
 Ac ........   conventional volume activity value  General Measure  No 0111 -OOP -C073 -16 
5 1.20  
sensitivity  
is the ratio of  the value obtained by measurement to the conventional activity value  
AB-IS
  (7) 
in which  I .....  is the value indicated when measuring a radioactive sample;  
 B ..........   is the value indicated when measuring without a radioactive sample;  
 A ..........   is the con ventional value of the activity of the sample measured  
1.21  
volume activity  
activity in relation to unit volume of air or gas  
1.22  
units  
this regulation uses the system of units SI ; the following secondary units are used where suitable:  
 for time: year (y),  day (d), hour (h), minute (min .); 
 for energy: electronvolt (eV);  
 for volume activity: becquerel per cubic metre (Bq/m3) 
1.23    
iodine monitor classification  
A device may be classified according to the type of detection device:  
 monitors for measuring the volume activity of radioisotope 131I only;  
 monitors for measuring the volume activity of radioisotope 125I or 129I; 
 monitors for overall measurement of all radioisotopes of iodine.  
A device may also be specified according to measurement method, such as:  
 devices with static absorption medium and simultaneous measurement;  
 devices with moving absorption medium and simultaneous measurement;  
 devices for the direct measurement of iodine in a chamber or pipe.  
2   Metrological requirements  
2.1   Defined operating c onditions  
An iodine monitor must meet the metrological requirements in the range of work temperature and 
relative air humidity specified by the manufacturer.  
2.1.1    Reference conditions and standard test conditions  
The reference conditions and standard t est conditions are listed in Table  1. 
Table  1 – Reference conditions and standard test conditions  
Influencing variables  Reference conditions  Standard test conditions  
Ambient temperature  20 °C 18 °C to 22  °C General Measure  No 0111 -OOP -C073 -16 
6 Relative air humidity  65 % 50 % to 75 %  
Air pr essure 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  Nominal frequency ±0.5  % 
Alternating supply voltage flow2) 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 m agnetic 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 con tamination  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 under standard test condi tions 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 test 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 relative error.  
2.5   Response to radioactive gases  
The manufacturer must specify the response to the respective radioactive gases present in the sample 
of air or carrier gas.  General Measure  No 0111 -OOP -C073 -16 
7 2.6   Response to ambient gamma radiation  
Since the relationship between respons e 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 specif y 
the decision level and the maximum value 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 input air kerma from the reference background inp ut 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 level.  
2.7   Overloading  
Unless the manufacturer and user agree otherwise, the device 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.  
2.8   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 obtain ed under standard conditions in a period of up to 30  minutes after 
being switched on.  
2.9   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 t he activity value caused by the statistical fluctuations must be less than 
10 % for values exceeding the first increment of 10 on the effective measurement range.  
2.10   Stability of values on detection and evaluation device  
The specification with the give n radiation source indicated after 30  minutes of device operation may 
not change by more than 10  % in the following 100 hours.  
2.11   Flow rate stability  
The purpose of this test is to establish the nominal flow rate of sampling and the stability of sampli ng 
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 ti me (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.  
2.12   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 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 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 u ser. 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.  
2.13   Influence of supply voltage on flow rate  
The flow rate may not change by more than 5  % if the supply volt age changes between +10  % and 
−12 % of the nominal supply voltage.  General Measure  No 0111 -OOP -C073 -16 
8 2.14   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. 
2.15   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.  
2.16   Ambient temperature  
The indicated specification must remain within the limits specified in Table  2 for the temperature 
range agreed upon by the manufacturer and user. It must be noted that, for this type of device, the 
detection and sampling device can work under other climatic conditions than the evalu ation 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  Devi ation from value under standard conditions  
+10 °C to +35  °C  
(median: +22  °C) ±10 % 
−10 °C to +40  °C  
(median: +15  °C) ±20 % 
–25 °C to +50  °C  
(median: +12  °C) ±50 % 
2.17   Relative air humidity  
The deviation caused by relative humidity up to 90  % at +35  °C must be less than 10  %. 
2.18   Sampling path efficiency  
The manufacturer must sp ecify the degree of absorption with both forms of iodine (organic form and 
elemental iodine) on a path leading from the sampling point to the filtration medium intended for 
capturing the radioactive iodine (filter, special cartridge)  
3   Technical requirem ents 
3.1   General requirements  
The main requirement for a device for monitoring radioactive effluents 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 devices for gaseous effluent monitoring under consideration are monitors of radioactive 
aerosols, monitors of rare gases and monitors with specific differentiation of radionuclides.  General Measure  No 0111 -OOP -C073 -16 
9 3.2.2    Iodine monitors  
This device usually includ es some kind of means of collection on a sampling medium, such as a static 
filter or moving 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 representative 
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 or 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 sourc es 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 representativeness 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 i t is used. Furthermore, it is necessary to prevent radioactive particles from 
gathering 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 
enviro nment 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 s ample is 
representative.  
NOTE  The following characteristics should be taken into consideration:  
 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;  
 surface treatment of internal surfaces;  
 radius of 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.  
3.4   Activity colle ction  
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 continuously 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 m ay be in the form of a belt or volume absorption granules in a 
suitably packaged system. After collection, the medium is exchanged and arranged so that one sample 
is measured and the next sample is collected.  General Measure  No 0111 -OOP -C073 -16 
10 3.5   Measurement and indication characteristi cs 
3.5.1   Effective measuring range  
The effective measurement range must be suitable 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 must be specified for specific radionuclides in consideration 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 specified in  Bq/m3 of the reference radionuclide 131I or mixture of iodine radioisotopes 131I, 
125I and 129I 
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 undetected malfunctions wherever 
possible.  
The manufacturer must provide documentation on the expected average service life of critical 
components such as the air p ump, 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 must be availabl e for failures to indicate that the system has a fault, such as a power cut or 
component malfunction.  
3.7   Sampling and detection devices  
3.7.1 Sampling and exhaust system  
The following characteristics are taken into consideration and must be agreed upon by the 
manufacturer and the user:  
 with the properties of the materials used, special attention must be paid to iodine absorption;  
 regulation of  the temperature of the air passing through to prevent condensation of the iodine or 
compounds thereof.  
3.7.2  Input filter  
If suitable, a filter may be positioned in the holder at the input to the sampling circuit in order to 
eliminate all dust and aerosol s. In order to retain the specific properties of the device, this filter may 
not capture, nor even temporarily retain, iodine (except in aerosol form).  
This component must also be placed sufficiently far away from the device ’s detector or must be 
shielded so that the filter ’s contribution to the value readout will be insignificant.  
3.7.3 Iodine capture medium  
The capture medium may have various geometries depending on the device ’s method of functioning  
The settling of iodine must be as homogenous as possible. Greater homogeneity can be achieved by 
using an annular current of air.  General Measure  No 0111 -OOP -C073 -16 
11 The de sign characteristics of the part for capturing iodine (dimensions, geometry, etc.) must take into 
consideration the characteristics of the capture medium used and the characteristics of the air (or gas) 
sampling pump.  
The presence of radioactive gases (suc h as 41Ar, 85Kr, 133Xe or 222Rn) in the gas being monitored may 
have an influence on the iodine monitoring. This primarily applies to non -selective detectors. In order 
to reduce the influence of these radionuclides, there must (if possible) be a small spac e of air near the 
detector and inside the iodine capture medium.  
The design must minimise leaks, especially internal leaks causing flow through a connector outside of 
the collection medium.  
Access to the iodine capture medium and filter must be made by a m eans which enables its quick and 
easy removal without damaging the radiation detector or components for capturing iodine. Also, the 
removal of the component for capturing iodine or the filter must not irradiate the operator with an 
excessive dose of radiat ion. 
The manufacturer must specify the service life of the iodine capture medium. This must be at least 
eight days for reference temperature and relative humidity conditions. The manufacturer must specify 
the sampling time at 90  % of relative humidity.  
3.7.4 Collection efficiency and capturing properties  
The manufacturer must specify the collection efficiency and capturing properties of the collection 
medium for elemental and unstable compounds of iodine under various load conditions.  
The iodine ’s contact ti me with the sampling medium should be greater than 0.2  seconds. If the contact 
time with the sampling medium is less than 0.2  seconds (such as in a monitor with a high flow rate), 
then reduced collection efficiency must be indicated. The actual collection efficiency must be 
specified by the manufacturer and agreed upon with the user.  
The manufacturer must specify how the collection efficiency is influenced by the chemical form of the 
iodine, the air conditions and the presence of chemical products in the sa mpled air. The manufacturer 
must specify the storage conditions of the collection medium.  
3.7.5  Radiation detector  
The manufacturer must fully specify the characteristics of the detector, including the detector ’s 
dimensions and transmission characteristics , such as its effective detection surface.  
If the cover of the detector is in direct contact with the gaseous medium being monitored, then special 
attention must be paid to the design so that the detector can be easily decontaminated.  
3.7.6   Pump  
If a pum p 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 main tenance 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 be able to maintain the required air or gas flow rat e regardless of pressure differences 
caused by standard operating conditions (maximum expected sampling time, iodine capturing 
elements used, dust in the air, etc.), i.e. at the end of sampling, there may not be any reduction 
vis-a-vis the nominal flow rat e greater than 10  % or error in the total sampled air volume value 
greater than 8  %;  
d) an alarm must be used which detects ruptures in the iodine capture medium (small pressure 
difference) as well as clogging of the medium (pressure difference greater than the value needed 
to reduce the flow rate by 10  %). General Measure  No 0111 -OOP -C073 -16 
12 3.7.7    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 sufficient to enable changes in the int rinsic characteristics of 
the air pump and all filters used.  
3.7.8    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 excessive change in flow rate. The f low 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 mu st be available. The necessary corrections must be made to the 
actual effluent conditions.  
3.7.9    Pressure control  
If the measurement method is sensitive to pressure within the measuring chamber, a device to measure 
the flow 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 manufacturer and the user.  
High -level al arms and malfunction alarms must provide separate local visual indication 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. Audio alarms must be provided.  
All alarm functions must have 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 operation point.  
Alarm circuits must f unction 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 adjustable alarm covering the entire  effective measurement range must be provided.  
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 malfunctions in the electronic system cir cuits.  
Alarms must indicate the source of the largest possible number of malfunctions and must have an 
automatic diagnostic system.  
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);  General Measure  No 0111 -OOP -C073 -16 
13  high-voltage power supply to detector on (if used);  
 flow or level of coolant supply for detector (if used).  
If air flows through the device, then a suitable flow measurement value must be provided.  
An output enabling re mote measurement and alarm indication must be provided.  
3.10   Means of checking operation  
Means must be provided which enable the user to periodically check that the device is operating 
satisfactorily, including calibration and linearity of measurement ve rification. These means must be 
installed so as to enable checks to be carried out from the control and evaluation unit.  
It must be possible to check the calibration of the device at two representative points in the 
measurement range.  
This check must be co nducted 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 testi ng points to simplify 
adjustments and fault localisation. All special instruments for maintenance and the necessary 
maintenance instructions must be supplied.  
The design of all devices must enable easy repair and maintenance.  
Information on automatic diagn ostic 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 su ction pipe;  
 container or other apparatus for eliminating short -term disruptive gaseous radionuclides;  
 means of removing samples for laboratory analysis and for calibration tests with radioactive 
gases;  
 device to cool the detector;  
 sampling chamber;  
 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 mu st be designed so as to minimise internal 
contamination and simplify decontamination when necessary. The outer surfaces should be specially 
treated to enable decontamination.  
The monitor must 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 such 
case, the device must be designed so as to prevent the possibility of the effluent being ignited by the 
instrument.  General Measure  No 0111 -OOP -C073 -16 
14 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 cooled from a local supply tank, it must not be necessary to fill up the tank more 
often than every eight days.  
3.13   Control and evaluatio n 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 s ituation central display panel. In such case, it must be 
possible to install it in electronic frames of normal dimensions.  
3.14   Ambient  background shielding or compensation devices  
These devices or procedures are used to reduce ambient background influen ce 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 must provide the same radiation attenuation in al l directions from the detector ’s 
sensitive surface area with consideration of the detection device ’s construction materials and the 
detector ’s angle responses. The thickness of the shielding must be determined with respect to the 
detector ’s detection effic iency.  
If it is not possible to easily remove the device from the shielding, this shielding must be easily 
dismantled, 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 directi on of radiation.  
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 desi gn 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 int erference from 
the surroundings and must meet the requirements of the applicable separate legislation2. The change in 
                                                      
2  Government Regulation  No 117/2016  on product conformity assessment regarding electromagnetic 
compatibility when supplied on the market  General Measure  No 0111 -OOP -C073 -16 
15 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 must be designed for op eration from single -phase alternating current voltage in one of the 
following categories according to:  
series  I: 230 V a.c.; 
series  II: 100 V a.c.; 
series  III: 120 V 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 switchover should be 
provide d. 
Three -phase power supply may be used for air pump motors.  
3.18   Protection against unauthorised tampering  
The parts of the measuring instrument essential to its metrological characteristics must be designed to 
be secured in such a way as to provide pro of of any unauthorised interference.  
If the measuring instrument ’s response can be adjusted by correcting the long -term change in 
response, correcting the influence of temperature and pressure on response or applying a corrective 
factor, then the measurin g instrument must be designed so as to prevent unintentional change of any 
adjustment factor by the operator.  
Control switches and potentiometers must either be inside the measuring instrument and inaccessible 
from the outside without using tools, or be c learly marked and fitted with a scale so that they can be 
precisely adjusted according to the resolution of the measuring instrument and then locked in order for 
the settings not to be changed accidentally. Correction factors and calibration coefficients s tored 
digitally may not be changed unless the operator enters the security code (or password) or changes the 
position of the blocked or inaccessible switch.  
3.19   Safety  
The measuring instrument must be safe in accordance with the basic principles of saf ety of ionising 
radiation installations and the requirements of relevant technical regulations under the conditions of 
normal use for the intended purposes.  
4   Measuring instrument markings  
4.1   Markings on the measuring instrument  
The following informat ion must be provided on each part of the measuring instrument, which may 
consist of two functionally separate parts:  
a) Manufacturer identification;  
b) Designation of the type of measuring instrument;  
c) Serial number of the detector(s), evaluation unit of the meas uring instrument, pump, flow meter;  General Measure  No 0111 -OOP -C073 -16 
16 d) type-approval mark;  
e) information on the safety of the ionising radiation measuring instrument.  
All labels and inscriptions must be legible, durable, unambiguous and unalterable.  
4.2   Placement of the official mark  
The pl acement of official marks on the detection part and the evaluation unit is specified in the type -
approval certificate.  
Where possible, marks 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 instruments  
5.1   General  
The measuring instrument type -approval process includes the following tests:  
a) External inspection;  
b) instrument accuracy;  
c) system linearity;  
d) response to radioactive gases;  
e) response to ambient  gamma radiation;  
f) overloading;  
g) detection and evaluation device uptake time;  
h) statistical fluctuation;  
i) stability of values on detection and evaluation device;  
j) flow rate stability;  
k) influence of pressure loss on the filter;  
l) influence of supply voltage on flow rate; 
m) influence of supply voltage frequency;  
n) external leak;  
o) influence of ambient temperature;  
p) influence of relative air humidity;  
q) sampling path efficiency (if part of the monitor);  
r) electromagnetic compatibility tests.  
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 completeness and status of the functional units of the measuring instrument according to the 
prescribed technical documentation;  
d) software versions ’ compatibility with the measuring instrument.  General Measure  No 0111 -OOP -C073 -16 
17 5.3   Functional tests  
5.3.1   Instrument 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 ir radiated with a suitable reference 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 value 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 prepara tion 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  % (for k = 2). The test sources must be linked to approved gauges.  
The tests may be carried out two ways:  
 with gaseous or solid radioactive sources;  
 with an electrical signal supply.  
Type tests are conducted at a single point on each scale for devices with a linear scale and on each 
increment 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 outer limit 
values. If electrical signals are used, they must be us ed at all ranges or increments of 10 (in addition to 
radionuclide sources).  
The measured value must not exceed the permitted change limits specified in Article  2.4. 
5.3.3    Response to radioactive gases  
The manufacturer must specify the response to the res pective 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 corre sponding 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 activity is fed into the system. The i odine 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 being tested.  
The measured value mu st not exceed the permitted change limits specified in Article  2.5. 
5.3.4    Response 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 i n operation, the response to gamma radiation and the 
decision level must be agreed upon by the manufacturer and the user. The manufacturer must specify General Measure  No 0111 -OOP -C073 -16 
18 the decision level and the maximum value 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 input 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 an d any gamma radiation energy up to 
1.3 MeV (60Co) may not exceed two times the value of the decision level.  
Test method:  
The device must work under standard test conditions without the presence of a radioactive source 
and the indicated background specifica tion 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  m and 
the conventional air kerma input value at the detector ’s location (as if the detector were n ot present) 
is 10 Gy/h  ± 10 %. The reference orientation of the 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 state has 
been reached, at least 10 readouts are carried out. The decision 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 then 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 it is not necessary to change the factor during this test. The 
readout on 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 the manufacturer and user, including a 
source of 60Co. If the evaluation device can be programmed wit h a compensation factor for gamma 
radiation, then it is not necessary to change the factor during this test. The readout on the evaluation 
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  2.6. 
5.3.5    Overload test  
Unless the manufacturer and user agree otherwise, the device must indicate a value off the scale at its 
upper end or indicate overloading when irradiated with a source with an act ivity (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 provi des a value of 
approximately 50  % of the first increment of 10 on the measurement range and the value 
readout is recorded.  
b) The detection device is exposed to a source of radiation with an activity 10 times greater than 
that which corresponds to the maximu m measurable value. The radiation is maintained for at 
least 10  minutes and it is verified that the instrument continuously shows a value off the scale at 
its uppermost end.  
c) The source of radiation is removed and, after a period of time agreed upon by the manufacturer 
and user (usually less than 1  h), the detection device is irradiated under the same conditions as 
in a). The values read out may not differ from the original value by more than 10  %. 
5.3.6    Detection and evaluation device uptake time  
When irr adiated with a radiation 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.  
The device must be disconnected from the ma ins for at least 1  hour prior to this test. A radiation 
source is used which provides a 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 General Measure  No 0111 -OOP -C073 -16 
19 for 1  hour. Ten hours after being turned on, a sufficient number of readouts is carried out in 
accordance with Article  5.3.7 and the mean 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 deviations at 
the low frequencies of impulse s measured.  
5.3.7    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 statistical fluctuations must be less tha n 
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 are 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 exceed the permitted change limits sp ecified in Article  2.9. 
5.3.8    Stability of values on detection and evaluation device  
The value indicated with the given radiation source after 30  minutes of device operation may not 
change by more than 10  % for the following 100 hours.  
A radioactive sour ce 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 specif ied in Article  2.10.  
5.3.9    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 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.  
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 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 permitted change limits specified in Article  2.11.  
5.3.10    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 normal conditions. An acceptable minimum drop in General Measure  No 0111 -OOP -C073 -16 
20 pressure which may cause a 10  % reduction from the nomin al 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.  
Test method:  
For this test, the monitor must be equipp ed 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, etc. 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 pressure 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 at standard test 
conditions. The conventional value of the sampling flow rate is measured under these conditions.  
The measured drop in pressure a nd flow rate must meet the requirements under these conditions.  
The measured value must not exceed the permitted change limits specified in Article  2.12.  
5.3.11    Influence of supply voltage on flow rate  
The supply voltage changes 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 upstr eam 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 vo ltage, 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 change limits specified in A rticle  2.13.  
5.3.12    Influence of supply voltage frequency  
The supply voltage frequency changes from 47  Hz to 51  Hz. 
Test method  
During this test, the sampling and detection device is connected to the nominal voltage supply and 
frequency, which changes f rom 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 low drop in pr essure 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 nominal frequency  and at specified limit frequencies.  
The measured value must not exceed the permitted change limits specified in Article  2.14.  
5.3.13    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.  
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 device. 
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 carried out at suita ble 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.  General Measure  No 0111 -OOP -C073 -16 
21 The measured value must not exceed the permitted change limits specified in Article  2.15.  
5.3.14    Ambient temperature  
With 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 conducted in an environmental chamber. Usu ally, 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 
temperature 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 within the applicable limits. In addition, the indicated 
specification is measured at the mean of the temperature range specified in Table  2. If the readou t 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 exceed the permitted change limits specifie d in Article  2.16.  
5.3.15    Relative air humidity  
With 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 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 Article  2.17.  
5.3.16    Sampling path efficiency test  
Sampling path eff iciency means the sampling pipe ’s ability to transport both chemical forms of 
radioactive iodine from the sampling point to the iodine capturing medium.  
A defined quantity of elemental 131I is released into the input of the sampling path. While it is bein g 
released, the growth in activity is monitored at the capture medium (hereinafter referred to as the 
filter). Once a stable value is reached, the total activity of 131I at the filter is determined. The ratio of 
release activity A1 and measured activity A2 is calculated with respect to the capture efficiency of the 
filter used. The result expressed as a per  cent expresses the sampling path efficiency. This parameter 
needs to be determined for the purpose of calculating the total release activity 131I throug h the 
ventilation system of the nuclear facility where the measurement is being conducted. It is also 
necessary to know the proportional representation of both basic chemical forms of iodine in the 
effluences (elemental iodine and the organic form of iodin e). 
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 sepa rate 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 the conductive surfac es and 
junction plates.  General Measure  No 0111 -OOP -C073 -16 
22 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 exceed the limits specif ied 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 instrument ’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 
subsequen t 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 switched on in a freq uency 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 d isturbances 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. Th e 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 wave 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 voltage 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 limits 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  3 and 4. The test is 
conducted with the device switched on by  measuring the disruptive terminal voltage at the power, General Measure  No 0111 -OOP -C073 -16 
23 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 measurement frequency . The 
highest value is measured, with the exception of random brief extreme values, which are ignored.  
The limits for the terminal voltage at the mains terminals are specified in Table  3. 
Table  3 – Limits for disturbances from power lines at mains termina ls 
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 inputs/outputs are specified in Table  4. 
Table  4 – Limits for disturbances from power lines at 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 disruptive electromagnetic field (radiated high -frequency interference)  
The monitor tested must comply with the interference limits s pecified in Table  5. The test is conducted 
with the device switched on by measuring the radiated electromagnetic field at a distance of 10  m. If 
the value of the measuring receiver fluctuates near a limit, then the value must be observed 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  5 – Limits of conducted radiation interference at a measurement range of 10  m 
Frequency range  
MHz  Quasi -peak li mits  
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) instru ment accuracy;  General Measure  No 0111 -OOP -C073 -16 
24 c) system linearity;  
d) response to ambient gamma radiation;  
e) overloading;  
f) statistical fluctuation;  
g) stability of values on detection and evaluation device;  
h) flow rate stability;  
i) influence of ambient temperature;  
j) sampling path efficiency (if part of the monitor).  
6.2   Visual inspection  
The visual 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 conduct ed pursuant to Article  5.3.2.  
6.3.3   Response to ambient gamma radiation  
The test is conducted pursuant to Article  5.3.4.  
6.3.4    Overload test  
The test is conducted pursuant to Article  5.3.5.  
6.3.5   Statistical fluctuation test  
The test is conducted pur suant to Article  5.3.7.  
6.3.6   Long -term stability test  
The test is conducted pursuant to Article  5.3.8.  
6.3.7   Long -term flow rate stability test  
The test is conducted pursuant to Article  5.3.9.  
6.3.8   Test of ambient temperature influence  
The test is conducted pursuant to Article  5.3.14.  
6.3.9    Sampling path efficiency test  
The test is conducted pursuant to Article  5.3.16.  General Measure  No 0111 -OOP -C073 -16 
25 7   Subsequent verification  
7.1   General  
During follow -up verification, the following tests are performed:  
a) external inspection;  
b) instrument accuracy;  
c) system linearity;  
d) overloading;  
e) stability of values on detection and evaluation device;  
f) flow rate stability;  
g) sampling path efficiency (if part of the monitor).  
7.2   Visual inspection  
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  5.3.5. 
7.3.4   Long -term stability test  
The test is conducted pursuant to Article  5.3.8.  
7.3.5   Long -term flow rate stability test  
The test is conducted pursuant to Article  5.3.9.  
7.3.6    Sampling path efficiency test  
The test is conducted pursuant to Arti cle 5.3.16.  
8   Measuring instrument 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. 1.25 
times the maximum permissible errors pursuant to Chapter  7 shall be applied as the maximum 
permitted error.  
9   Notified standards  
For the purposes of specifying the metrological and technical requirements for measuring instruments 
and specifying the testi ng methods for their type approval and verification arising from this General 
Measure, the CMI shall provide notification of the Czech technical standards, other technical General Measure  No 0111 -OOP -C073 -16 
26 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 mann er accessible to the public (at the website 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 legitimate interests.  
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, thi s measure of a general nature, stipulating 
metrological and technical requirements for specified measuring devices and test methods for type 
approval for verification of the following specified measuring devices – ‘Measuring instruments used 
to monitor act ivity limits and volume activity 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 env ironmental radiation exposure due 
to effluents – measuring instruments for the continuous monitoring of radioactive iodine in gaseous 
effluents from nuclear facilities ’.  
Decree  No 345/2002 laying down measurement instruments for mandatory validation and 
measurement instruments 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 validation.  
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 fie ld 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 t he 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 su bmitted in writing.  
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 o r how the general 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.  
 General Measure  No 0111 -OOP -C073 -16 
27  
 
 ................................ .......................   
RNDr. Pavel Klenovský  
Director -General  
 
 
Person responsible for accuracy: Mgr. Tomáš Hendrych  
 
Posted on:  
Signature of the authori sed person confirming posting:  ................................ ..............    
 
Removed on:  
Signature of the authorised person confirming removal:  ................................ ............