C z e c h  M e t r o l o g i c a l  I n s t i t u t e   
Okružní 31,  638 00  
Brno  
 
1. ------IND- 2012 0296 CZ - EN- ------ 20120518 --- --- PROJET 
As a body with material and local competence in matters concerning the establishment of metrological 
and technical requirements for the specified measurement device and the establishment of tes ting 
methods for type approval and during validation of the specified measurement device pursuant to 
Section 14 Paragraph 1 of Act No 505/1990 Coll. on metrology, as amended, and pursuant to the 
provisions of Section 172 et seq. of Act No 500/2004 Coll., t he Rules of Administrative Procedure 
(hereinafter referred to as ‘RAP’), the Czech Metrological Institute (CMI) has launched ex officio an 
administrative proceeding pursuant to Section 46 of the RAP on 10.2.2012, and, on the basis of the 
documentation, iss ues the following:  
 
 
I. 
GENERAL MEASURE  
Number:  0111 -OOP -C026 -12 
Reference No 0313/001/12/Pos.,  
 
 
establishing metrological and technical requirements for specified measurement devices, 
including testing methods for the type approval and validation of the specified measurement 
devices:  
‘thermometers for inspecting the temperature of frozen food products used by state inspection 
bodies’  
 
1   Basic definitions  
The terms and definitions pursuant to the VIM1) as well as the following terms and definitions shall  
apply for the purposes of this General Measure:  
1.1   Thermometer for inspecting the temperature of frozen food products:  A thermometer for 
measuring the internal temperature of frozen food products used by state inspection bodies (hereinafter 
referred to  as a ‘thermometer’) . 
                                                      
1)  International Vocabulary of Metrology – Basic and general concepts and associated terms (Mezinárodní metrologický slovník – Základní a všeobecné pojmy a přidružené 
termíny - VIM) General Measure No  0111 -OOP -C026-16 
2 1.2   Temperature sensor:  Element of a measurement device or measurement chain which is directly 
influenced by temperature . 
1.3   Internal temperature penetration sensor : Temperature sensor for measuring the temperature 
inside a froze n food product . 
1.4   Frozen food products:  Food products which have been subjected to a freezing process which is 
specifically designed to preserve the healthy state and quality of the product . 
1.5   Response time : The time between the moment when the input temperature value is exposed 
to a sudden step change between the two specified constant temperature values and the moment when 
the corresponding indication reaches 90% of its final stabilised value . 
1.6   Minimum temperature sensor submersion:  The sensor’s depth of submersion in a thermostatic 
bath with a temperature of ( –20 ± 2)°C at an ambient temperature of (23  ± 2)°C, in which the 
thermometer indication chan ges by a value of less than 0.1 °C when the sensor  is submersed deeper . 
1.7   Intrinsic error (of a measuring instrument):  A measuring instrument’s error in measurement 
determined under reference conditions prior to the commencement of the electromagnetic 
compatibility (EMC) tests.  
1.8   Fatal error (duri ng EMC tests):  A state found in EMC tests in the event that the difference 
between the measurement error determined during the EMC tests and the intrinsic error (of the 
measuring instrument) is greater than:  
a) a value of one third the value of the maximum pe rmissible error for thermometers with digital 
displays;  
b) the value of the maximum permissible error for thermometers with analogue displays.  
2   Metrological requirements  
2.1   Specified operating conditions  
Thermometers must meet the metrological requireme nts of operating ambient temperature within a 
range of (–20 to +55) °C and relative humidity  within a range of (10 to 95)%. 
The reference ambient temperature for thermometer testing is (23  ± 2)°C. 
2.2   Measurement interval  
The measurement interval for meas uring the internal temperature of frozen food product must be f rom at 
least –20.0 °C to + 30.0 °C. 
2.3   Maximum permissible error  
The maximum permissible error of a thermometer for measuring the internal temperature of frozen food 
products at reference amb ient temperature (23 ± 2)  °C must be ± 0.3 °C for thermometers with digital 
displays and  ± 0.5 °C for thermometers with analogue displays.  
2.4   Response time  
The thermometer’s response time  must  be less than 3 min.  General Measure No  0111 -OOP -C026-12 
3 3   Technical requirements  
3.1   General  
Thermometers for inspecting the temperature of frozen food products may be compact or may have 
structurally separate components.  The thermometer’s design configuration must enable it to be 
validated as a whole.  
All design elements of a thermometer fo r inspecting the temperature of frozen food products must be 
manufactured so as to guarantee the stability of the metrological properties and ensure reliable 
functioning  in long -term operation.   
The materials of the design components must be resistant to t he various forms of corrosion and wear 
which appear during regular operating conditions.  
The parts of the thermometer and accessories which come or may come into contact with food 
products must meet the hygienic requirements and legislation in effect in te rms of the design and 
materials used.  Said parts, as well as the transitions or cables between them, must have a smooth 
surface which enables them to be cleaned and disinfected easily.  
3.2   Temperature sensor   
The design configuration of temperature senso rs must allow them to be inserted into the frozen food 
products, or a tool which makes it possible to create a suitable opening for inserting the temperature 
sensor must be part of the accessories.  
The design configuration of a temperature sensor must be such that the sensor cannot be damaged 
during ordinary cleaning (in particular, water -tight construction, chemical resistance, mechanical 
resistance).  
Temperature sensors must be designed so that they can be submersed into thermostats’ operating 
liquid (s pirits, water, oil) without being damaged for the testing period during validation.  The 
minimum sensor submersion may not be less than 25  mm. The submersion of the temperature sensor 
of the thermometer being tested must be such that the heat dissipation do es not affect the 
thermometer’s display.  
In the case of thermometers with which the sensor’s protective housing  is made up of parts which 
conduct electricity and the insulation resistance value (resistance between the internal wiring and the 
sensor housing ) may affect the thermometer’s metrological properties, the insulation resistance va lue 
must be greater than 100   at a test  voltage of up to 100  V and at an ambient temperature of (15 to 
25) °C. 
If the length of the sensor's connecting cable to the displ ay equipment affects the metrological 
properties of the thermometer, the sensor must constantly be connected to the display equipment and 
access to the connecting terminals may not be enabled without breaking the official seals.   
3.3   Display equipment  
Analogue display equipment of a thermometer must have a scale value of ≤  0.5 °C. 
Digital display equipment of a thermometer must have a sensitivity of 0.1  °C. The numbers on the 
digital display must be larger than 4 mm.  
The unit of measurement for measuring the temperature of frozen food products is  °C. 
The outer covering must safely protect the display equipment from exterior effects which occur when 
the temperature of frozen food products is being measured (primarily from condensation moisture).  
3.4   Additional equipment  
A thermometer may be equip ped with recording equipment for monitoring the temperature’s time path 
in continuous (analogue) or digital form.  General Measure No  0111 -OOP -C026-16 
4 A thermometer may be equipped with a communication interface which enables additional equipment 
to be connected.  
3.5   Software  
With electron ic thermometers, the device’s software used must be identifiable (except in cases which 
exclusively involve displaying the measured values without other functions).  The software must be 
secured to prevent random or deliberate influence in the event of dama ge and must be in compliance 
with the technical standard document WELMEC 7.23). 
3.6   Power supply  
Thermometers may be supplied from the mains using an adapter, or may be supplied f rom an 
independent source.   
A thermometer with an external electricity supp ly must be able to connect to a power supply with a 
nominal value of 12 V or 24 V (alternating as well as direct current).   
Thermometers supplied from the mains must be supplied with alternating current UN within the range of  
UN – 15 % and UN + 10 %, in wh ich UN is the nominal supply voltage specified by the measurement 
device’s manufacturer, with a frequency of  fN  2 %. 
A voltage of UN ± 2 % and frequency of fN  0.4 % is used for reference purposes.  
An independent power source must be defined in the man ufacturer’s specifications, and the 
thermometer must signal that it requires new charging from the power source or that the power source 
must be replaced, and must be blocked from shutting off if the source voltage drops below the limit 
established by the manufacturer.  
3.7   Resistance to the effects of the outside environment  
3.7.1    Mechanical resistance   
The thermometer’s design and materials used must ensure sufficient strength, stability and resistance 
to mechanical impact and free fall.  
3.7.2    Resist ance to climatic conditions   
3.7.2.1    Boundary conditions for storage and transportation  
The thermometer or components thereof must be resistant to limit temperatures for storage of –30 °C 
and +70  °C. 
3.7.2.2    Degree of protection of the covering  
The cov ering’s degree of protection must be:  
– IP 65 for penetration temperature sensors;  
– IP 55 for display equipment and portable compact thermometers.  
3.8   Electromagnetic compatibility  
Thermometers which contain electronic components may not be influenced by el ectrical or 
electromagnetic interference, or they must react to such interference by defined means (such as by 
announcing an error, blocking measurement and similar).  In addition, they may not radiate an 
undesired electromagnetic field.  
                                                      
3) WELMEC 7.2 Software Guide; accessible to the public at www.welmec.org   General Measure No  0111 -OOP -C026-12 
5 The electromagnetic  environment  class  E1 is defined for thermometers containing electronic 
components (i.e. residential or commercial environment or light industry operating environment).  
3.9   Resistance to unauthorised manipulation  
Thermometers may not have properties whic h would facilitate fraudulent use; at the same time, the 
possibility of unintentional misuse must be minimal.  Components which the user is not allowed to  
disassemble or adjust must be secured to prevent such activity.  
The thermometer’s adjustment elements must be secured so that the settings cannot be changed during 
normal use without damaging the official seals.   
4   Gauge markings  
4.1  Markings on the measurement device  
The measurement devices must be clearly and visibly labelled with the following inform ation:   
– the manufacturer’s name or trademark;  
– the type of measurement device;  
– the serial number and year of production;  
– the measurement device’s type approval mark;  
– the operating temperature range;  
– the unit of measurement must be specified on the display e quipment (°C).  
If the temperature sensor can be disconnected from the display equipment, the label on the sensor must 
specify at least an unambiguous allocation of the sensor to the display equipment (such as a serial 
number) and space on the sensor's body  must be reserved for an official seal.  All data, specifications, 
information, etc. required in the articles of this Measure must be specified in the instructions on using 
the measurement device.  
4.2   Placement of official marking  
A space for attaching t he official seals must be prepared on the measurement device.  The placement of 
the official markings is defined in the type approval certificate.  
5   Measurement device  type approval  
5.1   General  
The thermometer type approval process encompasses the follo wing tests:  
– external inspection,  
– function tests:  
– insulation resistance test;  
– accuracy test;  
– determination of the response time;  
– test of resistance to external effects:  
– test of resistance to limit temperatures for storage and transportation;  
– test of protect ion from water seepage and infiltration by foreign particles (degree of 
protection of the covering ); 
– tests of resistance to supply voltage limit values:  General Measure No  0111 -OOP -C026-16 
6 – test of resistance to alternating current supply voltage limit values;  
– test of resistance to changes in  alternating current frequency;  
– tests of resistance to direct current supply voltage limit values;  
– electromagnetic compatibility tests:  
– test of resistance to high -frequency electromagnetic field radiation;  
– test of resistance to electrostatic discharge.  
5.2   External inspection   
The following is assessed during the external inspection:  
– completeness of the specified technical documentation;  
– conformity of the metrological and technical characteristics specified by the manufacturer in 
the documentation with the requirements of this regulation, specified in Articles 2, 3 and 4;  
– the completeness and condition of the thermometer according to the specified technical 
documentation;  
– conformity of the thermometer’s software version with the version specified by the 
manufacturer, if relevant (see Article 3.5).  
If severe shortcomings are detected, the measurement device will not be tested further.  General Measure No  0111 -OOP -C026-12 
7 5.3   Function tests  
5.3.1    Testing equipment  
The following equipment is used for the tests:  
a) ethanol thermometer with plat inum resistance temperature sensor with a measurement in terval 
of at least ( –30 to +50) °C and a combined measurement uncertainty of less than  0.03°C; 
b) liquid thermostat with a temperature  range of at least ( –20 to +30) °C enabling the testing of 
temperatur e sensors with submersion of at least 200 mm and with a combined standard 
measurement uncertainty induced by the homogeneity and stability of the temperature field of 
less than  0.03°C; 
c) apparatus for implement ing the thawing point of ice (0 °C) – Dewar fla sk for submersing 
sensors being tested by at least 200 mm;  
d) measurement equipment for measuring resistances (DC or AC) with a range depending on the 
type of ethanol resistance thermometer;  
e) stopwatch with a measurement range of at least 10 min.;  
f) insulatio n resistance measurement device – direct -current voltage of up to 100 V,  range of at 
least up to 100 M 
All measurement devices must have a valid relationship; the thermostat must have the specified and 
measured homogeneity and stability.  
5.3.2    Insulation resistance test  
With thermometers supplied by mains voltage, the insulation resistance is measured at ambient 
temperature between the conductors of the internal wiring and the electrically cond uctive covering of 
the sensor. The test is only conducted if the internal wiring conductors are accessible.  The test is 
conducted with direct current test voltage  of up to 100 V with both test voltage polarities; the result of 
the test is lower from both measured insulation resistance values.   
The measured value must meet the requirements for the insulation resistance value pursuant to Article 
3.2. 
5.3.3    Accuracy  test 
The accuracy test is conducted by establishing the measurement error in at least three temperature 
baths:  
– t1 = (–20 ± 2)°C; 
– t2 = 0°C; 
– t3 = (+30  ± 2)°C. 
In the test, the actual stabilised temperature  of the bath determined with the ethanol thermometer  is 
compared with the display on the thermometer being tested.  A series of at least four readouts from the 
ethanol thermometer and from the thermometer being tested is conducted for each testing temperature.  
The minimum submersion must meet the requirement  in Article 3.2.  
The measurement error at individual points may not exceed the maximum permissible error specified 
in Article 2.3.  
5.3.4    Determination of the response time  
The response time is determined in a thermostatic bath whic h is set at a temperatu re of 20 °C lower or 
higher than the initial temperature (such as the ambient temperature).  The thermometer is left to 
stabilise at the initial temperature and then the temperature sensor is submersed into the thermostatic General Measure No  0111 -OOP -C026-16 
8 bath as quickly as possible.  The t ime from the moment of the thermometer sensor’s submersion until 
the indication of 90% of the actual change in temperature is reached is measured.   
The response time ascertained may not exceed the response time specified in Article 2.4.  
5.4   Tests of resi stance to external effects  
5.4.1    Test of resistance to limit temperatures for storage and transportation  
The entire thermometer in an inoperative state (switched off, if relevant) must be placed in a 
climatised chamber for a period of three hours  at both  limit temperatures –30°C and +70 °C and at a 
rate of temperature change of 1 °C/min during the transition from one limit temperature to the other.  5 
cycles are conducted.  
The change in appearance is inspected immediately upon concluding the test.  The measur ement device 
may not change its appearance; the material and surface may not be frosted  or blistered and may not 
exhibit a change in colour.   
The thermometer must meet the requirements specified in Article 2.3 at the reference temperature 
once two hours ha ve elapsed as of the completion of the test.  
5.4.2    Test of protection from water seepage and infiltration by foreign particles (degree of 
protection of the covering)  
The test examines whether the measurement device meets the specified degree of protectio n pursuant 
to Article 3.7.2.2.  
NOTE   The ‘covering’ is considered to be the device’s cover in operational position, i.e. including connectors 
(with any potential closures), seals or other accessories.  
5.5   Tests of resistance to supply voltage limit valu es 
5.5.1    Test of resistance to alternating current supply voltage limit values;   
Resistance to alternating current supply voltage limit values is tested on the thermometer when it is 
switched on at the voltage limit values UN – 15% and UN + 10%, in which  UN is the nominal supply 
voltage specified by the manufacturer of the measurement device.  If the supply voltage is determined 
within the range of the nominal voltage values, the test will then be conducted at the lowest and 
highest voltage of the range.   
Measurement errors in supply voltage limit values may not exceed the maximum permissible error 
pursuant to Article 2.3.  
5.5.2    Test of resistance to changes in alternating current frequency   
Resistance to changes in supply voltage frequency is tested on a thermometer when switch ed on at the 
limit frequencies fN ± 2%, in which fN is the nominal supply voltage frequency.  
Measurement errors in supply voltage frequency limit values may not exceed the maximum 
permissible error pursuant to Article 2.3.  
5.5.3    Tests of resistance to direct current supply voltage limit values   
Resistance to direct current supply voltage limit values is tested on the thermometer when it is 
switched on at the voltage limit values Umin and Umax, in which Umin and Umax are the limit values of 
supply voltage specified by the manufacturer of the measurement device.  
Measurement errors in supply voltage frequency limit values may not exceed the maximum 
permissible error pursuant to Article 2.3.  General Measure No  0111 -OOP -C026-12 
9 5.6  Electromagnetic compatibility (EMC) te sts 
The electromagnetic compatibility tests are only conducted on thermometers containing electronic 
components.  
5.6.1    Resistance to electrostatic discharge  
Resistance to electrostatic discharge is tested on a thermometer when it is switched on, preferab ly 
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 thermometer’s covering and to the coupling panels in the 
vicinity of the thermometer.  
In this test, the the rmometer must demonstrate normal function ing in the limits of the maximum 
permissible error pursuant to Article 2.3, or it must ascertain a serious error and react to it by the 
defined means.  
5.6.2    Test of resistance to high -frequency electromagnetic fie ld radiation  
Resistance to high -frequency electromagnetic field radiation is tested on a thermometer when it is 
switched on in the following frequency zones and at the following test field intensities:  
– frequency 80  MHz to 800  MHz, intensity 3  V/m;  
– frequenc y 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 frequency step during the frequency sw eep of the test field is max. 1 %. The 
dwell time at each frequency may not be shorter than the time necessa ry to test out the thermometer, 
as well as its ability to react to interference.  However, it may not be shorter than 0.5 s under any 
circumstances.  The test field is applied to all sides of the thermometer’s covering.  
In this test, the thermometer must dem onstrate normal functioning within the limits of the maximum 
permissible error pursuant to Article 2.3, or it must ascertain a serious error and react to it by the 
defined means.  
6   Initial validation  
6.1   General  
The initial validation process for a the rmometer for determining the temperature of frozen food 
product encompasses the following tests:  
– visual inspection,  
– function tests:  
– insulation resistance test;  
– accuracy test.  
6.2   Visual inspection   
This visual inspection of the thermometer assesses wheth er: 
– the measurement device submitted for validation and its components conform with the 
approved type;  
– the measurement device and its components, including the connection cables, are not 
mechanically damaged and bear no signs of corrosion;  General Measure No  0111 -OOP -C026-16 
10 – the labelling, i nscriptions and configuration thereof correspond to the data and requirements 
specified in the measurement device’s type approval certificate.  
The measurement device will not be tested further if it does not meet the requirements of the visual 
inspection.  
6.3   Function tests  
6.3.1    Testing equipment  
The corresponding equipment pursuant to Article 5.3.1 shall be used for the tests.  
6.3.2    Insulation resistance test  
The insulation resistance test is conducted on new and repaired measurement devices pursua nt to 
Article 5.3.2.  
The thermometer will not be tested further if the measured value does not meet the requirements for 
the insulation resistance value pursuant to Article 3.2.  
6.3.3    Accuracy test  
The test of the thermometer’s accuracy shall be conduct ed pursuant to 5.3.3.  
The measurement error may not be greater than the maximum permissible error specified in Article 
2.3. 
7   Follow -up validation  
A procedure identical to the initial validation pursuant to Chapter 6 is applied during the follow -up 
valid ation, with the exception of Article 6.3.2.  
8   Declared standards  
The CMI declares Czech technical standards, other technical standards or technical documents of 
international or foreign organisations or other technical documents containing more detailed technical 
requirements (hereinafter referred to as the ‘declared standards’) for the purposes of specifying the 
metrological and technical requirements for measurement devices and for the purposes of specifying 
testing methods during validation based on th is General Measure.  The CMI announces a list of these 
notified standards assigned to the applicable measure together with the General Measure by means 
accessible to the public ( on the internet site www.cmi.cz).  
In the scope of and under the conditions esta blished by the General Measure, compliance with these 
declared standards or compliance with portions thereof is deemed to be compliance with said 
requirements established by the General Measure to which the these standards or portions thereof 
relate.  
 
 
II. 
GROUNDS   
The CMI issues this General Measure establishing metrological and technical requirements for the 
specified measurement devices and testing methods for the type approval and validation of said 
specified measurement devices for the purpose of imple menting Section 24c of Act No 505/1990 Coll. 
on metrology, as amended.  General Measure No  0111 -OOP -C026-12 
11 Regulation No 345/2002 Coll. establishing measurement devices for compulsory validation and 
measurement devices subject to type approval, as amended, classifies thermometers for inspect ing the 
temperature of frozen food products used by state inspection bodies  as measurement devices subject to 
type approval and v alidation under Item 3.1.3 in the  annex to the  Second List o f Specified 
Measurement Devices . 
Accordingly, the CMI is issuing th is General Measure establishing metrological and technical 
requirements for thermometers for inspecting the temperature of frozen food products used by state 
inspection bodies and testing methods for the type approval and validation of said specified 
measu rement devices for the specific measurement device type ‘thermometers for inspecting the 
temperature of frozen food products used by state inspection bodies’ for the purpose of implementing 
Section 24c of Act No 505/1990 Coll. on metrology, as amended.  
This Regulation (General Measure) was notified in accordance with European Parliament and Council 
Directive 98/34/EC of 22 June 1998 on the procedure for the provision of information in the field of 
technical standards and regulations and rules on Information  Society services, as amended by 
Directive 98/48/EC.  
 
 
III. 
LEGAL INSTRUCTIONS  
Legal remedies may not be applied against this General Measure (Section 173 Paragraph 2 of Act No 
500/2004 Coll., the Rules of Administrative Procedure, as amended (hereinafter referred to as the 
‘Rules of Administrative Procedure’).  
In accordance with the provisions of Section 172 Paragraph 5 of the Rules of Administrative 
Procedure, appeals may not be raised against decisions on objections.  
The General Measure’s conformity wit h the statutory regulations can be evaluated in the research 
procedure pursuant to the provisions of Section 94 to 96 of the Rules of Administrative Procedure.  The 
participant may submit a motion to conduct a research procedure to the administrative body w hich issued 
this general measure.  If the administrative body does not find reason to initiate a research procedure, it 
shall inform the submitter of this fact and substantiate its reasons within thirty days.  Rulings on the 
initiation of a research procedure may be issued within three years as of the General Measure’s entry into 
legal effect in accordance with the provisions of Section 174 Paragraph 2 of the Rules of Administrative 
Procedure.  
 
 
IV. 
ENTRY INTO L EGAL EFFECT  
This General Measure shall enter into legal effect on the fifteenth day as of the date of its 
promulgation (Section 24d of Act No 505/1990 Coll. on metrology, as amended).  
 
 
 
 
 
 ...…………………………..............  General Measure No  0111 -OOP -C026-16 
12  RNDr.  Pavel Klenovský,  
 General Dire ctor 
 
Responsible for the correctness of execution:  Ing. Miroslav Pospíšil  
 
Posted on:   
Signature of authorised person confirming posting:    ....................................................  
 
Removed on:  ..............................  
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