EN 50379-1:2004

SLOVENSKI SIST EN 50379-1:2005

STANDARD
december 2005
Specifikacije za prenosne električne naprave za merjenje parametrov
vnetljivosti izpušnega plina grelnih naprav - 1. del: Splošne zahteve in
preskusne metode
Specification for portable electrical apparatus designed to measure combustion flue
gas parameters of heating appliances – Part 1: General requirements and test
methods
ICS 13.040.40; 91.140.10 Referenčna številka
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

EUROPEAN STANDARD EN 50379-1
NORME EUROPÉENNE
EUROPÄISCHE NORM August 2004
ICS 13.040.40; 91.140.10
English version
Specification for portable electrical apparatus designed to measure
combustion flue gas parameters of heating appliances
Part 1: General requirements and test methods

Spécification pour les appareils Anforderungen an tragbare elektrische
électriques portatifs conçus pour mesurer Geräte zur Messung
les paramètres des gaz de combustion von Verbrennungsparametern
dans les conduits d'évacuation von Heizungsanlagen
des appareils de chauffage Teil 1: Allgemeine Anforderungen
Partie 1: Prescriptions générales und Prüfverfahren
et méthodes d'essai
This European Standard was approved by CENELEC on 2004-03-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50379-1:2004 E
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 216, Gas
detectors.
The text of the draft was submitted to the formal vote and was approved by CENELEC as
EN 50379-1 on 2004-03-01.
The following dates were fixed:
- latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2005-03-01
- latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2007-03-01
__________
– 3 – EN 50379-1:2004
Contents
Page
Introduction . 6
1 Scope . 7
2 Normative references . 7
3 Definitions. 8
4 General requirements. 9
4.1 General. 9
4.2 Construction. 10
4.2.1 General. 10
4.2.2 Sampling system . 10
4.2.3 Adjustments . 10
4.2.4 Power supply. 10
4.2.5 Display. 11
4.2.6 Measuring range and resolution. 11
4.2.7 Indication range. 11
4.2.8 Accuracy of the apparatus . 11
4.2.9 Detection limit . 11
4.2.10 Efficiency . 11
4.2.11 Printer or data storage. 12
4.3 Labelling and instructions . 12
4.3.1 Labelling . 12
4.3.2 Instructions . 13
5 Test methods . 13
5.1 General requirements for tests . 13
5.1.1 Samples and sequence of tests . 14
5.1.2 Preparation of samples. 14
5.1.3 Test facility. 14
5.2 Normal conditions for tests. 14
5.2.1 General. 14
5.2.2 Cylinder test gases. 14
5.2.3 Measurements on heating appliances . 16
5.2.4 Power supply. 16
5.2.5 Temperature . 17
5.2.6 Humidity. 17
5.2.7 Pressure . 17
5.2.8 Exchangeable parts. 17
5.3 Mechanical tests . 17
5.3.1 Degree of protection. 17
5.3.2 Impact strength . 17
5.3.3 Vibration . 17
5.3.4 Drop. 18
5.3.5 Flow indicator (if fitted) . 18
5.3.6 Dust filter and water trap . 18
5.4 Electrical and software tests. 18
5.4.1 EMC. 18
5.4.2 Supply voltage variations (not applicable to battery powered apparatus). 18

5.4.3 Battery fault condition (applicable only to battery powered apparatus) . 18
5.4.4 Battery reversal (applicable only to battery powered apparatus) . 18
5.4.5 Software and digital techniques . 18
5.5 Tests with test gases. 19
5.5.1 General. 19
5.5.2 Unpowered storage . 19
5.5.3 Initial performance. 19
5.5.4 Response time . 19
5.5.5 Cold start . 19
5.5.6 Zero reading. 19
5.6 Tests with real flue gases. 20
5.6.1 General. 20
5.6.2 Measurement uncertainty . 20
5.6.3 Low temperature (applicable only to apparatus designed for outdoor use) . 20
5.6.4 Stability under practical conditions. 21
5.6.5 Test of filter capacity . 21
5.6.6 Final test with cylinder gases . 21
5.6.7 Sensor replacement (where applicable) . 21
5.7 Calculated values. 21
5.7.1 General. 21
5.7.2 Calculation of CO gas volume ratio from O measurement. 21
2 2
5.7.3 CO/CO ratio . 21
5.8 Temperature . 22
5.8.1 Temperature measurement (flue gas) . 22
5.8.2 Flue gas temperature response time. 22
5.8.3 Temperature measurement (inlet air). 22
5.8.4 Inlet air temperature response time . 22
5.8.5 Cold start . 22
5.8.6 Thermocouple compensation. 22
5.8.7 High temperature. 22
5.9 Pressure .23
5.9.1 Pressure measurement (draught) . 23
5.9.2 Pressure measurement (differential) . 23

Annex A (informative) Standard combustion analysis procedures . 24
A.1 Combustion analysis in Germany. 24
A.2 Combustion analysis in the United Kingdom. 25
A.3 Combustion analysis in Italy . 26
A.4 Combustion analysis in Sweden. 27

Annex B (normative) Real flue gas measurements - Methodology and test methods . 30

Annex C (normative) Standard methods for determining measuring uncertainty . 33
C.1 Determination of the analytic function . 33
C.2 Determination of reproducibility . 33

– 5 – EN 50379-1:2004
Figure B.1 – CO, NO and SO variation with air ratio . 30
Table 1 – Requirements for accuracy. 11
Table 2 – Test gas mixtures for O and/or CO sensors. 14
2 2
Table 3 – Test gas mixtures for low range CO sensors. 14
Table 4 – Test gas mixtures for medium range²CO sensors . 14
Table 5 – Test gas mixture for high range CO sensors . 14
Table 6 – Test gas mixtures for NO sensors . 15
Table 7 – Test gas mixtures for SO sensors . 15
Table A.1 – Legal requirements for maximum waste gas loss. 22
Table A.2 – Parameters for calculation in Germany. 23
Table A.3 – Current standards for combustion efficiencies of domestic gas appliances
in the United Kingdom, based on dry air-free measurements . 23
Table A.4 – Legal requirements for combustion efficiency η in Italy . 24
Table A.5 – Parameters for heat loss calculation in Italy (reference UNI 10389). 25
Table B.1 – Minimum numbers of measurements . 28

Introduction
This European Standard covers apparatus for measuring gas concentrations and other combustion
parameters, as used in the installation and maintenance of heating appliances. It forms a
specification for portable electrical apparatus designed to measure combustion flue gas parameters
of heating appliances, and includes the following parts:
Part 1: General requirements and test methods;
Part 2: Performance requirements for apparatus used in statutory inspections and assessments;
Part 3: Performance requirements for apparatus used in non-statutory servicing of gas fired heating
appliances.
EN 50379-1 specifies general requirements for the construction, testing and performance of portable
spot reading apparatus designed to give an assessment of specific combustion flue gas parameters,
such as concentrations of gaseous compounds, temperature and/or pressure, to check the
combustion performance of heating appliances for domestic residential and commercial applications,
using commercially available fuels.
EN 50379-2 is for apparatus intended to be used for statutory measurement. In several European
countries, legal requirements exist for the performance of heating appliances (see Annex A).
Authorised inspectors use these apparatus to measure the flue gas parameters, in order to test
compliance with national regulations. Due to the legal consequences resulting from the
measurement, there are strict requirements regarding the measuring uncertainty of these apparatus,
and EN 50379-2 therefore includes maximum values for measuring uncertainty. Tests with real flue
gases form a key part of the verification of the performance of the apparatus for statutory
measurement. Measuring uncertainty has to be justified by internationally accepted methods over the
whole measuring range. The determination of measuring uncertainty is described in Annex C.
EN 50379-3 is for apparatus intended to be used for non-statutory applications. There are reduced
performance requirements, because the apparatus are designed to decide whether maintenance for
a gas fired appliance is required, and for adjusting the appliance during maintenance. There will be
no determination of the measuring uncertainty for the apparatus.

– 7 – EN 50379-1:2004
1 Scope
This European Standard covers apparatus for measuring gas concentrations and other combustion
parameters, as used in the installation and maintenance of heating appliances. Such apparatus may
be used for testing the performance of appliances for different types of fuels, either by the installer,
maintenance engineer or inspector.
The apparatus may consist of different functional modules, which may be tested separately for
complying with this standard and will be combined in different ways according to the different
applications. The apparatus shall comply with requirements as specified in EN 50379-2 and/or
EN 50379-3.
This European Standard specifies general requirements for the construction, testing and
performance of portable spot reading apparatus designed to give an assessment of specific
combustion flue gas parameters, such as concentration of gaseous compounds, temperature and/or
pressure, to check the combustion performance of heating appliances for domestic residential and
commercial applications, using commercially available fuels.
This standard excludes apparatus for
– continuous emission, safety monitoring and control, and
– use in vessels with an international load line.
NOTE 1  When this apparatus is used in industrial premises national regulations may apply.
NOTE 2  Apparatus may contain functional modules which are not covered by this standard e.g. measurement of smoke
spot number (see Annex A of EN 267).
2 Normative references
The following referenced documents are indispensable for the application of this document. For
dated references, only the edition cited applies. For undated references, the latest edition of the
referenced document (including any amendments) applies.
EN 267 Atomising oil burners of monobloc type - Testing
EN 297 Gas-fired central heating boilers - Type B11 and B11BS boilers fitted with
atmospheric burners of nominal heat input not exceeding 70 kW
EN 676 Forced draught burners for gaseous fuels
EN 50270 Electromagnetic compatibility - Electrical apparatus for the detection and
measurement of combustible gases, toxic gases or oxygen
EN 50271 Electrical apparatus for the detection and measurement of combustible
gases, toxic gases or oxygen - Requirements and tests for apparatus
using software and/or digital technologies
EN 50379-2 Specification for portable electrical apparatus designed to measure
combustion flue gas parameters of heating appliances -
Part 2: Performance requirements for apparatus used in statutory
inspections and assessment
EN 50379-3 Specification for portable electrical apparatus designed to measure
combustion flue gas parameters of heating appliances -
Part 3: Performance requirements for apparatus used in non-statutory
servicing of gas fired
EN 60068-2-6 Environmental testing - Part 2: Tests - Test Fc: Vibration (sinusoidal)
EN 60335-1 1994 Safety of household and similar electrical appliances -
Part 1: General requirements
EN 60359 Electrical and electronic measurement equipment - Expression of
performance
EN 60529 1991 Degrees of protection provided by enclosures (IP Code)
CR 1404 1994 Determination of emissions from appliances burning gaseous fuels
during type testing
ISO Guide GUM Guide to the expression of uncertainty in measurement
3 Definitions
For the purposes of this European Standard, basic definitions for statistical analyses are in line with
those given in Subclause 2.1 of EN 60359. In addition, the following definitions apply.
3.1
domestic residential and commercial premises
any place of residence of a household, family or person (whether temporary or permanent) and
commercial premises whether residential or not and including recreational boats, caravans and
mobile homes
3.2
ambient air
normal atmosphere surrounding the apparatus
3.3
clean air
ambient air which is essentially free of flue gas and of interfering or contaminating substances
3.4
sensor
assembly in which the sensing element is housed and which may contain associated circuit
components
3.5
sensing element
device, the output of which will change with variation of the parameter of interest
3.6
spot reading
apparatus intended to be used for short periods of time in the range of minutes, as required
3.7
volume ratio (V/V)
ratio of the volume of a component to the volume of the gas mixture under specified conditions of
temperature, pressure and relative humidity
3.8
mains powered apparatus
apparatus designed to be powered by the domestic mains electrical supply with or without an
additional power source
– 9 – EN 50379-1:2004
3.9
battery powered apparatus
apparatus designed to be energised from batteries alone, whether disposable or rechargeable
3.10
probe
part of the apparatus that is placed in the stack or flue of the heating appliance, for the purpose of
sampling the gas and/or for measuring temperature or pressure
3.11
initial start up delay
time taken for the apparatus to reach the operating mode from switch-on, or after replacing batteries,
or following power failure in the case of mains powered equipment
3.12
calibration
process of determining the deviation of an apparatus relative to a reference
3.13
reference
in laboratory tests, a reference gas will be a certified calibration gas cylinder. For real gas
measurement, the reference is a measuring device with high accuracy (e.g. as specified in EN 267).
For temperature and pressure measurement, the reference is a measuring device with certification
proving traceability to a national or international metrology institute
3.14
adjustment
process of tuning the apparatus, in order to return the deviation found in calibration to within the
admissible error
3.15
functional module
all components required for one measurement task, including both hardware and software. A
functional module may consist of one or more separate pieces of equipment or may be completely
integrated with the apparatus
3.16
response time (t )
time interval with the apparatus in a warmed-up condition, between the time when an instantaneous
variation of the parameter to be measured is produced at the apparatus inlet, and the time when the
response reaches and remains beyond 90 % of the final indication
4 General requirements
4.1 General
The apparatus shall reliably measure specific combustion flue gas parameters and shall clearly
display the result. If the apparatus is equipped with a sampling system (probe) the gas sample shall
be drawn into the unit for analysis via the sampling system for all tests. All parts of the apparatus
shall conform to the construction requirements of 4.2 and the performance requirements in
EN 50379-2 and/or EN 50379-3.
4.2 Construction
4.2.1 General
All parts of the apparatus, including the sensor(s), shall be constructed of materials that will not be
adversely affected by vapours and gases or chemical substances to be expected during normal
operation of the apparatus, see 4.3.2 g). Similar consideration shall also be given to the sampling
system and components that can be in contact with the gas, as appropriate. The probe shall be
constructed of materials that will not be adversely affected by environmental conditions found in
heating appliances within the scope of this standard.
4.2.2 Sampling system
The sampling system of the apparatus shall be so constructed as to prevent damage to the sensor(s)
and pump by particulate matter and liquids that may be expected during normal operation of the
apparatus. Means shall be provided to recognise and/or indicate the working mode of the pump by,
for example
– pump noise,
– visual indication, or
– flow measurement.
Condensation or absorption effects have to be considered, and shall have no significant influence on
the indicated values, particularly when determining SO and NO. The probe shall be constructed in
such a manner that droplets of condensation will not influence the result of temperature
measurements even when the probe is held vertically. In addition the temperature sensing element
shall not touch the probe outer sheath. If simultaneous recording of temperature and gaseous
compounds is required, the probe shall be constructed such that the distance between the sensing
element for temperature and the gas inlet, is less than 8 mm. If probes of different lengths are
provided the shortest and the longest shall be tested with the instrument.
NOTE For apparatus intended to measure heating combustion efficiency (see Annex A) reference shall be made to
national regulations where appropriate. Typically the following dimensions have been shown to be suitable:
- sampling probe immersion depth of at least 150 mm;
- probe external diameter between 6 mm and 13 mm (required for the measurement of heat loss only); and
- adjustable depth stop to be provided, to fix probe position and cover measuring aperture up to 21 mm diameter, to
prevent air ingress.
The method of testing tightness of the complete gas sampling system, as specified by the
manufacturer, shall be checked and verified for use in practice.
4.2.3 Adjustments
Access to sensitivity controls shall only be possible by the use of special tool or a software passcode
or by destroying a special seal. Any regular checks shall be performed automatically or by access as
described above.
4.2.4 Power supply
Apparatus which derives its power from internal batteries may give a visual warning before the
battery capacity falls to a point where either the apparatus sensitivity or the stated display accuracy
falls outside the requirements. When this point is actually reached, a clear indication shall be given to
alert the user and the display shall switch out of normal operational mode.

– 11 – EN 50379-1:2004
4.2.5 Display
Indicators shall be provided to show the following:
– measured parameter(s) and value(s);
– low battery warning;
– mode of operation or instrument status (e.g. warm-up, measurement); and
– when values lie outside the indicating range.
All values shall be indicated on a display with characters not less than 8 mm high unless adequate
provision is made for enhancing the legibility (e.g. backlighting) in which case the minimum character
height shall be 4 mm.
For each separate parameter measured the apparatus shall display the value, the physical unit and
parameter description. For a combination of parameters the display may switch automatically from
one indication to another. If the display switches between information of simultaneous parameters it
shall be clear and understandable. Displayed measured values shall be refreshed at intervals no
greater than 3 s. If the apparatus is equipped with seven-segment displays it shall have a device or
self testing function for checking the displays.
4.2.6 Measuring range and resolution
Table 1 lists the different parameters covered by this standard. For each parameter given it specifies
– minimum indication range,
– minimum display resolution,
– accuracy of the apparatus,
– the detection limit, and
– maximum response time.
4.2.7 Indication range
The indication ranges are the minimum ranges for the apparatus. Higher ranges are allowed, but will
not change the values for accuracy or detection limit.
4.2.8 Accuracy of the apparatus
The values in Table 1 e.g. “± 20 ppm or 5 % rel.” have the meaning: “The permitted deviation is up to
± 20 ppm or ± 5 % of the reading, whichever is the greater”.
4.2.9 Detection limit
Values indicated below the detection limit are not significant.
4.2.10 Efficiency
Efficiency is not included in the table as determination varies considerably from country to country
(see Annex A for further details).

Table 1 – Requirements for accuracy
Display Detection Response
Parameter Indication range Accuracy
resolution limit time (t )
CO (low)
0 - 200 ppm 1 ppm ± 10 ppm or 10 ppm 90 s
10 % rel.
CO (medium)
0 - 2 000 ppm 1 ppm ± 20 ppm or 20 ppm 90 s
5 % rel.
CO (high)
0 - 20 000 ppm 10 ppm ± 100 ppm or 100 ppm 90 s
10 % rel.
NO
0 - 600 ppm 1 ppm ± 5 ppm or 5 ppm 90 s
5 % rel.
SO
0 - 500 ppm 1 ppm ± 10 ppm or 10 ppm 180 s
5 % rel.
O
0 - 21 % V/V 0,1 % ± 0,3 % V/V 0,3 % V/V 50 s
CO
0 - 20 % V/V 0,1 % ± 0,2 % V/V 0,2 % V/V 50 s
Temperature 0 - 400 °C 1 °C ± 2 °C or 1 °C 50 s
(flue gas) 1,5 % rel.
Temperature 0 - 100 °C 1 °C ± 1 °C 1 °C 70 s
(inlet air)
Pressure
-50 to +200 Pa 1 Pa ± 2 Pa or 1 Pa 10 s
(draught)
5 % rel.
Pressure 0 - 10 000 Pa 10 Pa ± 50 Pa or 100 Pa 10 s
(differential) 1 % rel.
a a
Heat loss
0 - 100 % 0,1 % N/A N/A N/A
b b
CO/CO ratio
0 - .01 0,0001 N/A N/A N/A
a
Calculated from the fuel characteristics and measured parameters - either O or CO , temperature of flue gas and
2 2
temperature of inlet air, in accordance with national regulations.
b
Calculated from the fuel characteristics and the measured parameters of CO and either O or CO , in accordance with
2 2
national regulations.
4.2.11 Printer or data storage
If the apparatus is provided with a printer or any means for data storage e.g. a data logger it shall
print the date, time and values of all parameters, as specified in 4.2.6, taken at the time of the
printout.
4.3 Labelling and instructions
The text used for labels and instructions shall be in accordance with appropriate national regulations.
4.3.1 Labelling
Durable label(s) shall be carried on the apparatus, or moulded into the casing, giving at least the
following information:
a) the manufacturer’s or supplier’s name, trademark or other means of identification;
b) the type of apparatus, e.g. “combustion gas analyser”, and model name or number;
c) either the number of this European Standard or the third party certification;

– 13 – EN 50379-1:2004
d) the manufacturer’s serial number and/or production batch date code;
e) the replacement battery and mains power requirements, as relevant;
f) whether or not the instrument is suitable for outdoor use (see 5.3.1, 5.5.3 and 5.6.3).
Item (e) shall be clearly visible if the batteries are being changed.
External label(s) shall comply with Subclauses 7.6 and 7.14 of EN 60335-1.
4.3.2 Instructions
The apparatus shall be provided with an instruction manual giving complete, clear and accurate
instructions for the safe and proper operation and regular checking of the apparatus. It shall also
include the following:
a) a statement of compliance with Part 2 and/or Part 3 of this European Standard, specified for the whole
apparatus or for the defined functional module(s);
b) the specific type(s) of fuel for which the apparatus is intended to be used;
c) the correct battery type(s) and method of replacing or recharging batteries, for battery powered units,
details of mains voltage, frequency and fuse rating, if relevant, and a warning of the possible hazards of
electric shock or malfunction, if tampered with;
d) warnings against continuous use, or use as a safety alarm;
e) an explanation of all indications;
f) for apparatus complying with Part 2, the recommended minimum time required to perform one complete
measurement cycle and achieve correct indication of the measured values(s);
g) for apparatus complying with Part 3, the recommended minimum time required for one checking
procedure;
h) a list of commonly occurring materials, vapours or gases (e.g. cleaning fluids, polishes, paints, cooking
operations, etc.) which may affect the operation or reliability of the apparatus, in the short or long term;
i) guidance on the life expectancy of the sensor(s) and batteries;
j) details of operational limitations, including ambient temperature and humidity ranges, and whether the
apparatus is intended to be placed in an appropriate case during transportation and/or normal operation;
k) details of initial start up delay following switch on and after battery replacement;
l) instructions for checking, testing and/or replacing sensing elements (where applicable) dust filter and
water trap, and calibration and/or adjustment of the apparatus on a routine basis;
m) a warning that, when using the apparatus, a full visual inspection of the appliance must also be carried
out to ensure its safe operation.
5 Test methods
5.1 General requirements for tests
The manufacturer shall specify for which fuel(s) and for which parameters or combination of these,
the apparatus or module(s) shall be tested as described in this clause and shall comply with the
performance requirements listed under the corresponding clause numbers in Part 2 and/or Part 3 of
this standard. All relevant tests of this standard shall be carried out.
Apparatus may contain functional modules which are not covered by this standard, e.g. measurement
of smoke spot number (see EN 267, Annex A).

If the apparatus has a modular structure allowing different combinations of parameters to be
measured and displayed with different accessories, such as with probes or filters fitted, it shall
clearly state in the manual which parameters and combinations are tested to comply with which parts
of this standard or additional standards (e.g. EN 267).
NOTE  Modules added at a later stage for additional parameters may be tested separately.
5.1.1 Samples and sequence of tests
Details of the samples needed and the sequence of testing to be followed are given in 5.1.1 of Part 2
or Part 3 of this standard, as appropriate. Tests shall first be carried out to ensure that the apparatus
satisfies the constructional requirements of 4.2, as appropriate. The mechanical tests of 5.3 shall be
carried out before the tests of 5.4 to 5.9.
5.1.2 Preparation of samples
The sample apparatus shall be prepared in accordance with the manufacturer's instructions. If the
apparatus is normally used in its carrying case then the test shall be carried out with the apparatus in
the carrying case.
5.1.3 Test facility
The construction of the test gas delivery system shall be such as to ensure that the gas sensor(s) are
exposed to a specific volume ratio of test gas in a reproducible manner. The flow rate of test gas
shall be matched to the sampling rate of the apparatus without causing significant pressure
variations.
5.2 Normal conditions for tests
5.2.1 General
The normal test conditions in 5.2.2 to 5.2.8 shall be used for all tests unless otherwise specified.
5.2.2 Cylinder test gases
Gas measurements:
i) expose the apparatus to the relevant test gas mixtures, as specified below, for 3 min, or 5 min
when exposed to test gases in 5.2.2.6;
ii) expose the apparatus to clean air until the indication is below the detection limit, or for a
maximum of 3 min or 10 min for test gases in 5.2.2.4 and 5.2.2.6.
Repeat i) and ii) above until all relevant test gas mixtures have been applied. In addition to recording
the displayed reading of the appropriate test gases also record the displayed reading of all other
relevant gases.
The cylinder test gases listed below shall be
– used to perform the tests in 5.3.3, 5.3.4, 5.4.2 to 5.4.4, 5.5.3 to 5.5.5, 5.6.5, 5.6.6 and 5.7.3,
– within the range of ± 5 % relative (for volume ratios below 100 ppm within ± 10 % relative) of the
volume ratios given in the tables, but known within ± 2 % relative and greater than 99,99 % purity
for nitrogen.
– 15 – EN 50379-1:2004
5.2.2.1 Test gas mixtures for O and/or CO sensors
2 2
When fitted with an oxygen and/or carbon dioxide sensor the apparatus shall be tested with gases of

known volume ratio as shown in Table 2.
Table 2 – Test gas mixtures for O and/or CO sensors
2 2
a
Gas mixture O CO CO SO C H Balance
2 2 2 3 8
1 1,6 % 12,0 % 950 ppm 80 ppm 70 ppm Nitrogen
2 5,0 % 9,0 % 150 ppm 80 ppm 70 ppm Nitrogen
3 16,5 % 2,5 % 950 ppm 80 ppm 70 ppm Nitrogen
a
To be omitted, at the manufacturer’s request, when the apparatus under test is intended only for use with natural gas
and/or LPG.
5.2.2.2 Test gas mixtures for low range CO sensors
When fitted with a sensor for measuring carbon monoxide in the low range the apparatus shall be
tested with gases of known volume ratio as shown in Table 3.
Table 3 – Test gas mixtures for low range CO sensors
a
Gas mixture CO H Balance
1 150 ppm 75 ppm Air
2 50 ppm
 Air
a
To be omitted, at the manufacturer’s request, when the apparatus under test is intended only for EN 50379-3.
5.2.2.3 Test gas mixtures for medium range²CO sensors
When fitted with a sensor for measuring carbon monoxide in the medium range the apparatus shall
be tested with gases of known volume ratio as shown in Table 4.
Table 4 – Test gas mixtures for medium range²CO sensors
a
Gas mixture O CO H CH Balance
2 2 4
1 2,5 % 950 ppm 500 ppm  Nitrogen
2 ----- 950 ppm Air
 
3 ----- 150 ppm  150 ppm Air
a
To be omitted, at the manufacturer’s request, when the apparatus under test is intended only for EN 50379-3.
5.2.2.4 Test gas mixture for high range CO sensors
When fitted with a carbon monoxide sensor for the high measuring range the apparatus shall be
tested with gas of known volume ratio as shown in Table 5 in addition to the gas mixtures shown in
Table 4.
Table 5 – Test gas mixture for high range CO sensors
Gas mixture CO Balance
1 8 000 ppm Air
5.2.2.5 Test gas mixtures for NO sensors
When fitted with a nitric oxide sensor the apparatus shall be tested with gases of known volume ratio
as shown in Table 6.
Table 6 – Test gas mixtures for NO sensors
Gas mixture NO Balance
1 50 ppm Nitrogen
2 200 ppm Nitrogen
3 450 ppm Nitrogen
5.2.2.6 Test gas mixtures for SO sensors
When fitted with a sulphur dioxide sensor the apparatus shall be tested with gases of known volume
ratio as shown in Table 7.
Table 7 – Test gas mixtures for SO sensors
Gas mixture SO Balance
1 50 ppm Air
2 200 ppm Air
3 450 ppm Air
5.2.3 Measurements on heating appliances
For flue gas measurement under realistic conditions (including the influence of high humidity and
cross interferences with other compounds of the flue gas) it is essential to test with heating
appliances using the type(s) of fuel for which the apparatus is designed. The following appliances
shall be used for the relevant tests:
a) atomizing oil burners of monobloc type (for extra light fuel oil) as defined in EN 267;
b) automatic forced draught burners for gaseous fuels as defined in EN 676;
c) gas-fired central heating boilers with atmospheric burners as defined in EN 297.
For apparatus designed to measure the flue gas of gaseous fuels, both types of burners b) and c) shall be used.
Suitable appliances for additional type testing with solid fuels (e.g. coal and wood) or other types of
fuel will be chosen at the discretion of the test house. In this case, the test house shall take particular
care to keep detailed records of all test conditions.
5.2.4 Power supply
Unless otherwise specified for the particular test mains voltages shall be within ± 2 % of the nominal
values quoted by the manufacturer. Battery powered apparatus shall be fitted with new or fully
charged battery/batteries at the start of each test, where appropriate.
For flue gas tests only the mains voltage supply may be allowed to vary ± 10 % from nominal values.

– 17 – EN 50379-1:2004
5.2.5 Temperature
Unless otherwise specified for the particular test the ambient air and test gas mixtures shall be at a
constant temperature ± 2 °C, within the range 15 °C to 25 °C for the duration of each test.
For flue gas tests only the ambient air temperature may rise to a maximum of 40 °C.
5.2.6 Humidity
Unless otherwise specified for the particular test the ambient air shall be at a constant relative
humidity ± 10 % within the range 30 % to 70 % for the duration of each test.
5.2.7 Pressure
Except for 5.8.7 tests shall be performed using air, test gas and real flue gas at constant pressure
± 1 kPa within the range of 86 kPa to 108 kPa throughout the duration of the test.
5.2.8 Exchangeable parts
If the manufacturer supplies different types of accessories or optional filters, water traps and/or
probes for the same parameter measurement, then the apparatus shall be tested under the
conditions which give the most unfavourable result for the test being conducted.
5.3 Mechanical tests
5.3.1 Degree of protection
The enclosure of the apparatus shall provide at least an IP40 degree of protection when all probes
etc. are connected, in accordance with Clauses 12 and 14 of EN 60529. If an apparatus is designed
for outdoor use it shall provide at least an IP42 degree of protection when connected similarly. The
apparatus shall be tested in accordance with Clauses 12 and 14 of EN 60529.
5.3.2 Impact strength
The apparatus shall be tested in accordance with the test specified in Clause 21 of EN 60335-1, with
the following modification to the third paragraph:
“The apparatus is rigidly supported, and three blows are applied to every point of the enclosure that
is likely to be weak with an impact energy of (1,0 ± 0,2) J.”
The apparatus shall be subjected to this test in a case intended to provide protection during
transportation, if one is supplied with the apparatus. Subject the apparatus to one of the most
appropriate test gas mixtures as described in 5.2.2.
5.3.3 Vibration
The appropriate test, as defined in EN 60068-2-6, shall be applied with the following parameters:
- frequency
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