The Czech Metrology Institute  
Okružní 31, 638 00 Brno  
 
1. ------IND- 2015 0535 CZ - EN- ------ 20151007 --- --- PROJET 
 
Executive summary for the European Commission ( not part of this legislation ) 
Optical radiometers for spectral range of 400  nm to 2  800 nm and measurement of emitted radiation 
in the range 10 3 W/m2 to 102 W/m2 are placed on the market and put into operation in the Czech 
Republic as specified measuring instruments with type approval and initial verification pursuant to 
Act No  505/1990, on metrology, as amended. The subject of this notified legis lation is national 
metrological regulation of type approval and verification of instruments for measuring illuminance.  
This regulation sets forth the metrological level required for recognition of measuring instrument type 
approval and verification certifi cates issued abroad to be recognised.  
(End of executive summary.)  
Ref. No: 0313/001/15/Pos.  
Compiled by: Engineer Miroslav 
Pospíšil  
Telephone: 545  555 135, -131 
As the authority with substantive and territorial jurisdiction in the matter of laying down m etrological 
and technical requirements for specified measuring instruments and stipulating test methods for type 
approval and verification of specified 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 Administrative Code (hereinafter the “AC”), the Czech 
Metrology Institute (hereinafter the “CMI ”) commenced ex officio proceedings on 15  May 2015 
pursuant to  § 46 of the AC, and based on the supporting documents, hereby issues the following:  
I. 
M E A S U R E  O F  A  G E N E R A L  N A T U R E  
number: 0111 -OOP -C046 -15 
Ref. No   0313/001/15/Pos.,  
 
stipulating metrological and technical requirements for specified measurement devices, 
including testing methods for the type approval and verification of the specified measurement 
instruments:  
“optical radiometers fore spectral range of 400  nm to 2  800 nm and measurement of emitted 
radiation in the range 10-3 W/m-2 to 102 W/m-2” Measure o f a General Nature No  0111 -OOP -C046 -15 
2 1 Basic def initions  
The terms and definitions pursuant to the VIM a VIML1) as well as the terms and definitions specified 
in the following shall apply for the purposes of this measure of a general nature.  
1.1 
optical radiometer   
a measuring instrument for measuring q uantities characterising optical radiation  
1.2 
broadband radiometer   
a radiometer for measuring energy and power characteristics of optical radiation over the entire 
measurement range from 3  × 1011 Hz to 3  × 1016 Hz, which corresponds to wavelengths from 1  × 10-
8 m to 1  × 10-4 m including ultraviolet (UV), visible, and infrared (IR) radiation  
1.3 
filtered (integral) radiometer   
a radiometer that has its relative spectral responsiveness adjusted to an effective (actinic) spectrum of 
specific characteristics;  adjustment of relative spectral responsiveness may be achieved using suitable 
optical filtering of incident radiation  
1.4 
UV radiometer   
a radiometer for measuring energy and power characteristics of optical radiation over the range 
7.5 × 1014 Hz to 4  × 1014 Hz, which corresponds to wavelengths from 1  × 10-9 m to 4  × 10-7 m in the 
lower part of the visible spectrum (below violet)  
1.5 Basic characteristics of optical radiometers  
1.5.1  
responsivity R  
the ratio of optical radiation at the detector's input to  the measurable signal at its output:  
XYR
 
where  
X  is the optical radiation energy at the detector's input;  
Y  is the measurable signal at the detector's output.  
NOTE  The term responsiveness aptly describes the specifics of optical radiometers, and replaces the term 
sensitivity, which is a general one in metrology.  
1.5.2  
spectral (monochromatic) responsivity R(λ)  
is defined by the following relationship:  



 

XY
dXdY
dXdY
dXdYR )()()(
 
where  
                                                      
1) The International Vocabulary of Metrology – Basic and General Concepts and Associated Terms (VIM) and 
the International Vocabulary of Terms in L egal Metrology (VIML) are part of the technical harmonisation 
compendium “Terminology in the Area of Metrology ”, which is publicly accessible at www.unmz.cz..  Measure of a General Nature No  0111 -OOP -C046 -15 
3 X(λ)  is radiation in the spectral interval 0 -λ and its derivative is the sp ectral concentration of radiant 
energy;  
Y(λ)  is the signal in the spectral interval 0 -λ and its derivative is the signal for spectral 
concentration of radiant energy.  
Suitable optical filtration of incident radiation is often used to adjust the relative s pectral responsivity 
of a filtered (integral) radiometer.  
1.5.3  
relative spectral responsivity  r(λ)  
for a given wavelength 
0  is defined as  
)()(
0RRr
 
where 
0 is the relative wavelength  
NOTE  In the case of non -linear detectors, the relative spectral responsivity is defined as the ratio of spectral 
responsivities corresponding to a constant value of the signal Y(λ) over the entire relevant spectral range.  
1.5.4  
linearity  
a detector property based on which the output quantity is directly proportional to the input quantity; 
deviations from linearity, i.e. non -linearity in a given input quantity range with a maximum value of 
Xmax is described by a characteristic function:  
 1max
maxXX
YYYfL
 
where  
Ymax is the maximum signal value at the output of the detector (radiometer)  Y; 
Xmax the maximum value of the input quantity X 
NOTE  If the detector has several ranges with non -linearity characteristics that are different from the non -
linearity of the entire range, t he characteristic with the greatest value is taken into account.  
1.5.5  
actinism a(Z)  
the sensitivity of integral responsivity to changes in the spectral composition of the input quantity S(λ) 










d r Sd S
d Sd r S
Za
NN
ZZ
 
where  
r(λ)  is the relative responsivity;  
N or Z  is the spectral composition of a reference or unknown source.  
1.5.6  
quantum efficiency η  
the ratio of elementary events participating in the input signal to the number of incident photo ns. 
For photoelectric detectors whose output signal is an ele ctric current, the quantum efficiency for a 
given wavelength  is calculated from the spectral responsivity as follows:  

qch R
 Measure o f a General Nature No  0111 -OOP -C046 -15 
4 where  
h  is Planck's constant;  
c  is the speed of light in a vacuum;  
q  is the elementary charge.  
NOTE  Quantum eff iciency taken relative to incident photos is external quantum efficiency η (λ). If the reference 
value is the number of photos absorbed by the detector, this is internal quantum efficiency ηt (λ). 
1.5.7  
additional characteristics of optical radiometers   
pursuant to the general definition of responsivity, optical radiometers are  also characterised by other 
parameters that affect its value:  
– the influence of temperature;  
– directional sensitivity;  
– polarisation sensitivity.  
1.6 specific characteristics of filtered (integral) radiometers  
In light of definition 1.2, filtered (integral) radiometers are described by the characteristic below.  
1.6.1  
relative spectral responsivity S*(λ)  
is given by the spectral weighting function s(λ)u and is specified over the entire spectral range of the 
prescribed spectral weighting functions, which ideally should be provided in tabular form at 1  nm 
increments.  
If the spectral increment is greater,  it will be necessary to select a suitable mathematical form of 
interpolation. Comparison of the actual and required function, while taking into account the spectral 
characteristics of the source used for calibration, expresses the normalised relative spec tral 
responsivity  




s
d s Sd s S
S
ku k





0,0,
 
where  
Sλ,k  is the spectral distribution of energy in the spectrum of the calibration source;  
s(λ)u  is the spectral weighting function characterising the effect of radiation;  
s(λ) is the detector's relative spectral responsivity.  
1.6.2  
spectral correction coeffi cient    
corrects the failure of the relative spectral responsivity of the detector in use to match to the prescribed 
weighting function.  
If the spectral distribution of energy in the spectrum of the calibration and measured source is known, 
relative respon sivity is defined as  










0,0,
0,0,




d s Sd s S
d s Sd s S
Za
u ZZ
ku k
 
where  
Sλ,k  is the spectral distribution of energy of the calibration source;  Measure of a General Nature No  0111 -OOP -C046 -15 
5 Sλ,Z  is the spectral distribution of energy of the source in the given application;  
s(λ)u  is the spectral weighting function of the effect;  
s(λ) is the detector's relative spectral re sponsivity.  
Measurement of a source Z using a radiometer calibrated using source K can be corrected, and the 
corrected value is  
ZaYYZ
 
where  
YZ  is the measured value for the source;  
Z and a(Z)  are the relative responsivity and its inverte d value;  
1/a(Z)  is the spectral correction coefficient.  
1.7 
baseline error (of a measuring instrument)   
the measurement error of a measuring instrument with a digital readout determined under reference 
conditions prior to the start of electromagnetic comp atibility (EMC) tests.  
1.8 
serious error (during EMC tests)   
a state of affairs determined during EMC tests if the difference between the measurement error 
determined during EMC tests and the baseline error (of the measuring instrument) is greater than 1/3 of 
the maximum permitted error of an optical radiometer with a digital readout.  
2 Metrological requirements  
2.1 Operating conditions  
Operating conditions are defined by the optical radiometer manufacturer.  
2.2 Measuring range  
Broadband radiometers have an  optical radiation measuring range from 3  × 1011 Hz to 3  × 1016 Hz. 
UV radiometers have an optical radiation measuring range from 7.5  × 1014 Hz to 1.5  × 1015 Hz. This 
corresponds to wavelengths 2  × 10-7 to 4 × 10-7m. 
Filtered (integral) radiometers have va rying measurement ranges depending on the radiometer's 
specific actinic spectrum.  
2.3 Accuracy  
Accuracy requirements for optical radiometers are stipulated by the manufacturer depending on their 
specific application or specific actinic function.  
2.4 Spectr al responsivity  
2.4.1  The manufacturer must specify spectral responsivity over the entire measuring range.  
2.4.2  If a broadband radiometer based on the use of photoelectric detectors whose output signal is 
an electric current, its spectral responsivity can  be quantified as the quantum efficiency for the given 
wavelength  calculated from the spectral responsivity.  
2.4.3  For filtered radiometers, the manufacturer must specify spectral responsivity matching s(λ) of 
the relevant relative spectral weighting function s(λ)u over the entire measuring range.  Measure o f a General Nature No  0111 -OOP -C046 -15 
6 This responsivity must be specified in the entire spectral range of the specified spectral weighting 
function, which should ideally be depicted in tabular form wi th increments of 1  nm. If the spectral 
increment is greater, it will be necessary to select a suitable mathematical form of interpolation.  
The degree to which the relative spectral responsivity of the detector in use does not match the 
prescribed weighting  function can be quantified as a normalised spectral responsivity or as a spectral 
corrective coefficient.  
2.4.4  For an integral filtered radiometer, the manufacturer must specify the matching of its spectral 
responsivity s(λ) to the relevant weighting function.  
2.4.5  The manufacturer must specify the actinism of a broadband radiometer relative to a reference 
source of radiation in the case of declared use for measurement of specific sources of radiation.  
2.4.6  In the case of  declared use of an optical radiometer for measurement of optical radiation at 
discrete wavelength values (e.g. a laser radio meter), the radiometer's spectral responsivity may be 
stipulated for only these specific wavelengths.  
2.5 Linearity  
The manufactur er must specify an optical radiometer's linearity within the specified measuring range.  
NOTE  If an optical radiometer is used to measure time -varying signals, the manufacturer must also specify the 
response time and the frequency range.  
2.6 Other character istics  
2.6.1  Temperature dependence  
The manufacturer must specify the measuring instrument ’s temperature dependence.  
Unless otherwise specified by the manufacturer, temperature dependence measurement is performed 
by comparing an optical radiometer's readou t at 23  °C and at 35  °C. 
2.6.2  Directional responsivity  
The manufacturer must specify an optical radiometer's directional sensitivity.  
The difference between the value given by the optical radiometer when the radiation's angle of 
incidence is β and the value during perpendicular incidence is measured, multiplied by the value of cos 
β. 
NOTE  During verification of optical radiometers, perpendicular incidence is always used, and so the effect of 
directional error is not taken into account. In prac tice, however, light may fall on the optical radio meter's sensor 
at various angles, which means this influence must be quantified.  
2.6.3  Polarisation responsivity  
If a radiometer is irradiated with linearly polarised radiation and the azimuth angle of the  radiation 
changes, a detector sensitive to polarisation exhibits changes in the signal Y in accordance with this 
change in azimuth polarisation angle. If the maximum and minimum signal value Y is specified, then 
the polarisation sensitivity is given by:  

min maxmin max
Y YY Y

 
where ε is the angle of incidence on the detector.  Measure of a General Nature No  0111 -OOP -C046 -15 
7 3 Technical requirements  
3.1 In general  
The basic parts of an optical radiometer are an optical radiation detector and a converter that converts 
the detector's signal to the measured value characterising the radiation impinging on the detector.  
Optical radiometers must be of solid construction and must be manufactured from suitably strong and 
sturdy materials in order to withstand the normal conditions of use and environments they are 
subjected to without malfunctioning or suffering undesired changes in their metrological parameters 
over time.  
The measuring range of optical radiometers may be increased by using adapters with calibrated neutral 
filters or opto -mechanical apertures that a re installed on their detector part.  
An optical radiometer's wavelength range must be declared.  
An optical radiometer must resist, without damage, its measurement range being exceed by 100  % for 
at least 10 minutes and by 20  % permanently.  
3.2 Optical radi ation detector  
A detector's design and built must meet the following requirements:  
– easy and stable fixation during measurement (attachment threads or a level surface);  
– a protective cover (to protect the optically active surface from physical damage);  
– a non -removable detector direction mark (for polarisation -dependent sensors only);  
– detector tempering function indication;  
– the detector's power cord, if any, must not prevent its handling and positioning during 
measurement;  
– easily -attached adapters with neutral  filters or opto -mechanical apertures (when measurement 
range of optical radiometers needs to be increased).  
3.3 Display device  
A digital display device must have the proper resolution for the optical detector. The numerals must be 
larger than 4  mm. It mus t be possible to zero the display.  
3.4 Auxiliary equipment  
Auxiliary equipment for optical radiometers is as follows:  
– special optical filters to adjust the detector's actinism;  
– optical apertures;  
– stable thermocouples to adjust the detector's operating temp erature;  
– special light sources with required stable power sources;  
– a recording device for long -term measurement in continuous (analogue) or digital form;  
– a standard data interface for further processing of measured values.  Measure o f a General Nature No  0111 -OOP -C046 -15 
8 3.5 Software  
A manufacturer of op tical radiometers with a data interface must supply a PC data evaluation program 
with the measuring instrument. The software must be secured to prevent random or deliberate 
influence in the event of damage and must be in compliance with the WELMEC 7.22) guide. 
3.6 Power supply  
Optical radiometers may be powered from the mains using an adapter, or may be powered from an 
independent source. Power from the mains must be an AC voltage UN within the range UN – 15 % 
and UN + 10 %, where UN is the nominal supply v oltage specified by the measuring instrument's 
manufacturer, with a frequency of fN  2 %. 
For reference purposes, a voltage of UN ± 2 % and a frequency of fN  0.4 % are used.  
The independent source of power (a battery) must be defined in the manufacturer 's specifications. The 
optical radiometer must indicate that it must be recharged from the power source or that the power 
source must be replaced, and must block itself or shut off if the supply voltage drops below the limit 
set by the manufacturer.  
Batter y-powered optical radiometers must be able to indicate the battery level.  
3.7 Resistance to outdoor environmental effects  
3.7.1  Temperature limits  
An optical radiometer and all its parts must be able to withstand temperatures extremes of –30 °C and 
+70 °C without damage and deterioration of its metrological characteristics.  
3.7.2  Ingress protection (IP)  
Optical radiometers must be rated at IP 40 or better. Measuring devices intended for laboratory use, 
with emphasis on accuracy, are an exception.  
3.8 Electr omagnetic compatibility (EMC)  
Optical radiometers must not be influenced by electrical or electromagnetic interference, or must react 
to such interference by defined means (such as by reporting an error, blocking measurement, and 
similar). In addition, the y may not radiate an undesired electromagnetic field.  
An electromagnetic environment class of E1 is defined for all optical radiometers (i.e. a residential, 
commercial, or light industry operating environment).  
3.9 Tamper -resistance  
Optical radiometers may  not have properties that would facilitate fraudulent use, and the possibility of 
unintentional misuse must be minimal. Components that the user is not allowed to disassemble or 
adjust must be secured to prevent such activity.  
An optical radiometer's adjus tment elements must be secured so that the settings cannot be changed 
during normal use without damaging the official seals.  
4 Measuring instrument markings  
4.1 In general  
All writing and symbols must be easily visible, legible and indelible under normal c onditions.  
Every optical radiometer must bear at least the following information:  
                                                      
2)    WELMEC 7.2 Software Guide; available to the public at www.welmec.org  Measure of a General Nature No  0111 -OOP -C046 -15 
9 – the manufacturer ’s name;  
– type designation;  
– the serial number of the measuring instrument and detector (if detachable);  
– the measuring ranges and unit of measurement used;  
– powe r supply;  
– the type approval mark.  
4.2 Official marks  
It is necessary to ensure sufficient room for the type approval mark and official mark(s) fulfilling the 
following requirements:  
– the mark is placed on a non -detachable part of the measuring instrument;  
– it does not cover up other markings on the device;  
– it is placed at a location where the label cannot be damaged during normal use of the device.  
If an optical radiometer is equipped with an opening for access to adjustment elements affecting the 
measuring i nstrument's basic parameters, it must be possible to cover this opening by sealing it over 
with a marking label. In the same manner, it must be possible to seal at least one screw on a cover that 
must be removed from the device to access its adjustment ele ments with a marking label.  
5 Measuring instrument type approval  
5.1 In general  
The type approval process consists of the following tests:  
– external inspection;  
– preliminary function test;  
– accuracy test;  
– linearity test;  
– spectral responsivity test;  
– temperatur e dependence test;  
– directional dependence test;  
– test of resistance to external effects:  
– resistance to limit temperatures;  
– test of protection from water seepage and infiltration by foreign particles (level of 
protection by the cover);  
– test of immunity to su pply voltage limit values;  
– test of immunity to AC supply voltage limit values;  
– test of immunity to AC frequency changes;  
– test of immunity to DC supply voltage limit values;  
– electromagnetic compatibility (EMC) tests;  
– test of resistance to radiated high -frequency electromagnetic fields;  
– test of resistance to electrostatic discharge.  Measure o f a General Nature No  0111 -OOP -C046 -15 
10 5.2 External inspection  
An external inspection of an optical radiometer assesses:  
– that the required technical documentation is complete;  
– that the metrological and technical charac teristics specified by the manufacturer in the 
documentation conform to the requirements of this regulation, specified in Articles  2, 3 and 4;  
– that the optical radiometer is complete and its condition corresponds to required technical 
documentation;  
– the op tical radiometer's software version matches the version specified by the manufacturer.  
5.3 Preliminary functional test  
The optical radiometer must be placed in a temperature stabilised laboratory for a sufficient length of 
time for its temperature to adjus t before measuring commences.  
The optical radiation detector is attached to the holder at optical zero and the indicator is placed in the 
prescribed position.  
A cursory check of the optical radiometer's functionality is conducted in an undarkened radiometr ic 
laboratory by measuring a light -emitting background in the laboratory environment.  
After the detector is covered, the measuring instrument's zero indication is checked and set if 
necessary.  
5.4 Accuracy test  
5.4.1  Test equipment requirements  
Testing opt ical radiometers requires the following measuring instruments with verified metrological 
traceability and other tools:  
– spectral responsivity standards — reference detectors with calibrated spectral responsivity and 
linearity values;  
– an optical system of a double monochromator with a suitable light source covering the given 
spectral range. The monochromator's entry and exit slits must have an adjustable width with 
the ability to adjust spectral resolution to (1 to 15  nm). The monochromator's wavelength scale  
must be calibrated with expanded uncertainty of ±0.2 throughout the intended spectral range 
(for k = 2). The degree of suppression of the effect of scattered light on spectral responsivity 
must not exceed a relative value of 1  × 10-4; 
– a reflective or tran smissive display system ensuring the shaping of the monochromator's exit 
radiation beam;  
– a turntable with an angular scale with 1° divisions. The turntable must permit attachment of 
the radiometer's detector head for angular sensitivity tests;  
– thermometer with a measurement range of (15 –40 °C); 
– a photometric current gauge (nano -ammeter or current -to-voltage converter) with a sensitivity 
and input impedance adjusted to the parameters of reference spectral responsivity detectors.  
5.4.2  Assembly of the measuri ng system - apparatus  
Assemble measuring and measured devices to fulfil the conditions stipulated in Chapter  2. In doing so, 
ensure that active elements (sensors) are located in such a way as to prevent changes in their mutual 
positions (spatial location) during measurement. The measurement itself of optical radiometers is 
performed using a reference radiometer on a double monochromator with a suitable light source 
covering the given spectral range. The monochromator serves as a tunable source of quasi -Measure of a General Nature No  0111 -OOP -C046 -15 
11 mono chromatic radiation. A beam of optical radiation is applied alternately to the active surface of the 
optical radiometer under verification and the reference radiometer. The monochromator apparatus is 
composed of a monochromator, a suitable source of light,  an opto -mechanical measuring system 
located in a lightproof casing on the exit side of the monochromator, measuring and control 
instruments and computers with suitable software. The system is supplemented with an ambient 
temperature monitor with automatic  storage of values during measurement. The entire system is fully 
automated for time -consuming tasks lasting several hours.  
5.4.3  Accuracy test  
The accuracy of an optical radiometer is tested by comparing its signals with those of a reference 
detector. The  reference and then the tested detector are alternately placed into the measuring beam. 
Output signal levels are recorded for both detectors upon optical beam incidence and after the aperture 
is closed. The entire measuring process is controlled by the sof tware of the apparatus, which performs 
automatic measurement and storage of measured values.  
During the test, measurement errors must not exceed maximum permitted errors specified by the 
manufacturer.  
5.5 Linearity test  
For optical radiometers, a linearity  test is performed using the superposition method over the power 
range specified by the manufacturer. The test can also be performed via direct comparison with the 
reference linearity detector at several defined optical power output levels.  
During the test , measurement errors must not exceed maximum permitted errors specified by the 
manufacturer.  
5.6 Spectral responsivity test  
The responsivity of an optical radiometer under verification is performed on the system described in 
Article  5.4.3 according to the relationship described in Article  1.5.1.  
The correction coefficient is then determined as the ration between the output value measured by the 
reference optical radiometer Pref and the value measured by the tested radiometer PDUT. 
DUTref
PPCF
 
The value measured by the tested measuring device is corrected by multiplying it by the correction 
coefficient.  
During the test, measurement errors must not exceed maximum permitted errors specified by the 
manufacturer.  
5.7 Temperature dependence test  
The opt ical radiation detector is placed in a suitable environmental chamber placed on a movable dolly 
in a lightproof chamber. At a temperature of 23  °C, a beam from the monochromator (corresponding 
to that from the radiation source) is admitted into the closed lightproof chamber, and the detector's 
signal value is measured.  
Then the temperature in the environmental chamber is increased to 35  °C, and after stabilising for 30 
minutes, a beam is once again emitted from the monochromator onto the detector in the lig htproof 
chamber. During the test, measurement errors must not exceed maximum permitted errors specified by 
the manufacturer.  
5.8 Measurement of an optical radiometer's directional dependence  
During this test, the sensor is attached to a turntable on a mova ble dolly in a lightproof chamber. The 
sensor is set so that the turntable ’s axis passes through the centre of the sensor ’s sensitive surface and Measure o f a General Nature No  0111 -OOP -C046 -15 
12 is perpendicular to the optical axis of the photometric bench. Directional dependence is measured 
within a ran ge from 5° to 85° at increments of 5° or less, according to the manufacturer ’s 
requirements.  
Directional dependence can be measured in two ways:  
– keeping the detector at a constant distance from the radiation source, complete measurement 
of directional depe ndence is performed by turning the sensor;  
– at a constant angle β, specific intensity values are set by changing the aperture in the optical 
path.  
NOTE  Measurement at a constant distance is simpler, but linearity errors in the radiation detector's radiometric 
scale apply. Measurement using variable source intensity eli minates the influence of radiometric scale non -
linearity on measurement.  
During the test, measurement errors must not exceed maximum permitted errors specified by the 
manufacturer.  
5.9 Test of resistance to limit temperatures  
The complete radiometer must b e placed, switched off, in an environmental chamber for three hours at 
limit temperatures of –30 °C and +70  °C and with a rate of change of 1  °C/min when switching from 
one limit temperature to another. Five cycles are performed.  
An inspection is performed  for changes in appearance immediately upon concluding the test. There 
may be no change in the measurement instrument ’s appearance; the material and surface must not be 
cracked or blistered or exhibit a change in colour.  
After two hours have passed after t he end of the test, the optical radiometer must be fully functional 
without any changes to characteristics declared by the manufacturer.  
5.10 Test of protection from water seepage and infiltration by foreign particles (level of 
protection by the cover)  
This test involves determining whether the measuring instrument meets the specified protection level 
pursuant to Article  3.7.2.  
NOTE  The cover is defined as the instrument's cover in its operating position, i.e. including connectors (with 
any closures, seals,  or other accessories).  
5.11 Test of immunity to supply voltage limit values  
5.11.1  Test of immunity to AC supply voltage limit values  
Resistance to AC supply voltage limit values is tested with the optical radiometer switched on at 
voltage limit values UN – 15 % and UN + 10 %, where UN is the nominal supply voltage specified by 
the measuring instrument's manufacturer. If the supply voltage is specified within a range of nominal 
voltage values, the test is performed at the lowest and highest voltage values.  
During the test, measurement errors at limit values of supply voltage must not exceed maximum 
permitted errors specified by the manufacturer.  
5.11.2  Test of immunity to AC frequency changes  
Immunity to supply voltage frequency changes is tested with the o ptical radiometer switch on at 
frequency limit values fN ± 2 %, were fN is the nominal frequency of the supply voltage.  
During the test, measurement errors at limit values of supply voltage frequency must not exceed 
maximum permitted errors specified by th e manufacturer.  Measure of a General Nature No  0111 -OOP -C046 -15 
13 5.11.3  Test of immunity to DC supply voltage limit values  
Resistance to DC supply voltage limit values is tested with the optical radiometer switched on at 
voltage limit values Umin and Umax, where Umin and Umax are the limit supply voltage  values specified 
by the measuring instrument's manufacturer.  
During the test, measurement errors at limit values of supply voltage must not exceed maximum 
permitted errors specified by the manufacturer.  
5.12 Electromagnetic compatibility (EMC) tests  
5.12. 1 Resistance to electrostatic discharge  
Resistance to electrostatic discharge is tested on an optical radiometer when it is switched on, 
preferably using voltage of ±6  kV for contact discharge and ±8  kV for air discharge if contact 
discharge cannot be used . The discharges are applied to the optical radiometer's cover and to coupling 
panels in the radiometer's vicinity.  
In this test, the optical radiometer must function normally within the limits of the maximum 
permissible error specified by the manufacturer , or it must ascertain a serious error and react to it in a 
defined manner.  
5.12.2  Resistance to a high -frequency radiated electromagnetic field  
Resistance to a radiated high -frequency electromagnetic field is tested on optical radiometers when 
they are sw itched on in the following frequency bands and at the following test field intensities:  
– frequency 80  MHz to 800  MHz, intensity 3  V/m;  
– frequency 800  MHz to 960  MHz, intensity 10  V/m;  
– frequency 960  MHz to 1  400 MHz, intensity 3  V/m;  
– frequency 1  400 MHz to 2  000 MHz, intensity 10  V/m.  
The test field ’s specified intensity values apply to measurement without modulation. The test field ’s 
amplitude is modulated with a depth of 80  %; the modulation signal has a sine wave with a modulation 
frequency of 1  kHz. The ma ximum frequency step during the frequency sweep of the test field is 1  %. 
The dwell time at each frequency may not be shorter than the time required to test the optical 
radiometer, including its ability to react to interference. In no event, however, may i t be shorter than 
0.5 s. The test field is applied to all sides of the optical radiometer device's cover.  
In this test, the optical radiometer must function normally within the limits of the maximum 
permissible error specified by the manufacturer, or it mu st ascertain a serious error and react to it in a 
defined manner.  
6 Initial verification  
6.1 In general  
The initial verification process consists of the following tests:  
– visual inspection;  
– preliminary function test;  
– accuracy test;  
– linearity test;  
– spectral responsivity test.  Measure o f a General Nature No  0111 -OOP -C046 -15 
14 6.2 Visual inspection  
During visual inspection, the optical radio meter submitted for verification is checked to determine 
whether it (including its software version) conforms to the approved type. Special attention must be 
paid to ensur ing the markings pursuant to Article  4.1 are correct and legible.  
The optical radiometer is also inspected for physical damage. Optical radiometers with an electronic 
display are checked to determine whether all characters on the display are visible after the device is 
connected to the mains power supply.  
Optical radiometers that do not conform to the approved type or are damaged are not tested further.  
6.3 Preliminary functional test  
A preliminary function test is conducted pursuant to Article  5.3. 
6.4 Accuracy test  
An accuracy test is conducted pursuant to Article  5.4. 
6.5 Linearity test  
The linearity of the optical radiometer being verified is tested pursuant to Article  5.5. 
6.6 Spectral responsivity test  
The spectral responsivity of the optical radiom eter being verified is tested pursuant to Article  5.6. 
7 Subsequent verification  
The subsequent verification procedure is identical to that for initial verification pursuant to Chapter  6. 
8 Notified standards  
To specify metrological and technical requireme nts for measuring devices and to specify verification 
and type approval test methods stemming from this measure of a general nature, the CMI notifies 
Czech technical standards, other technical standards or technical documents of international or foreign 
organisations or other technical documents containing detailed technical requirements (hereinafter 
“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 www.cmi.cz ). 
Compliance with notified standards or parts thereof shall be considered, to the extent and under the 
conditions stipulated in the measure of a general nature, as compliance with tho se requirements 
stipulated in this measure to which these standards or parts thereof apply.  
 
 
II. 
J U S T I F I C A T I O N  
The CMI issues, pursuant to §  14(1)(j) of the Metrology Act, towards the implementation of §  6(1), 
§ 9(1), §  9(9), and §  11a(3) of the Metrology  Act, this measure of a general nature, stipulating 
metrological and technical requirements for specified measuring devices and test methods for 
verification of these specified measuring devices.  
Decree No  345/2002, specifying measuring instruments for man datory verification and measuring 
instruments subject to type approval, as amended, classifies optical radiometers for the spectral area of 
400 nm to 2  800 nm and measurement of radiation in the range 10-3 W/m-2 to 102 W/m-2 as measuring Measure of a General Nature No  0111 -OOP -C046 -15 
15 instruments subjec t to type approval and verification of specified measuring instruments under 
Item 5.1.1 in the annex “List of Specified Measuring Device Types ”. 
The CMI thus issues, towards the implementation of §  6(1), §  9(1), §  9(9), and §  11a(3) of the 
Metrology Act, f or the measuring instrument type specified as “optical radiometers for the spectral 
area of 400  nm to 2  800 nm and measurement of radiation in the range 10-3 W/m-2 to 102 W/m-2”, this 
measure of a general nature, stipulating metrological and technical requ irements for optical 
radiometers for the spectral area of 400  nm to 2  800 nm and measurement of radiation in the range 10-3 
W/m-2 to 102 W/m-2 and test methods for type approval and verification of these specified measuring 
instruments.  
This regulation (Me asure of a General Nature) has been notified in accordance with 
Directive  98/34/EC of the European Parliament and of the Council of 22  June 1998 on the procedure 
for the provision of information in the field of technical standards and regulations and of ru les on  
Information Society services, as amended.  
 
III. 
I N S T R U C T I O N S  
A measure of a general nature cannot be appealed (§  173(2) of the Administrative Code).  
Pursuant to §  172(5) of the Administrative Code, a decision on objections cannot be appealed.  
Compli ance of the measure of a general nature with legislation may be subject to a review process 
pursuant to §  94 to §  96 of the Administrative Code. A party to the proceedings may initiate review 
proceedings to be conducted by the administrative authority that  issued the measure of a general 
nature. If the administrative authority finds no reason to commence review proceedings, it shall 
communicate and provide grounds for this to the submitter within 30 days. Pursuant to §  174(2) of the 
Administrative Code, a r uling on the commencement of review proceedings can be issued within three 
years of the effective date of the measure of a general nature.  
 
 
IV. 
E F F E C T I V E  D A T E  
This measure of a general nature takes effect on the fifteenth day following the date of its pub lication 
(§ 24d of the Metrology Act).  
 
 
 
...………………………… ..............  
RNDr. Pavel Klenovský  
Director General