IEC 60079-29-1:2016

IEC 60079-29-1 ®
Edition 2.0 2016-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 29-1: Gas detectors – Performance requirements of detectors for flammable
gases
Atmosphères explosives –
Partie 29-1: Détecteurs de gaz – Exigences d’aptitude à la fonction des
détecteurs de gaz inflammables
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IEC 60079-29-1 ®
Edition 2.0 2016-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Explosive atmospheres –
Part 29-1: Gas detectors – Performance requirements of detectors for flammable

gases
Atmosphères explosives –
Partie 29-1: Détecteurs de gaz – Exigences d’aptitude à la fonction des

détecteurs de gaz inflammables

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-5030-3

 IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-29-1
Edition 2.0  2016-07
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors –
Performance requirements of detectors for flammable gases

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
31/1456/DISH 31/1462/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

___________
In accordance with Administrative Circular AC/42/2004: New procedures for interpretation of
standards, Annex 2: New text for ISO/IEC Directives (IEC Supplement), there has been a
request for formal interpretation of the Air Velocity test acceptance criterion in the
performance standard IEC 60079-29-1:2016.
Question:
Is the acceptance criteria for the Air Velocity test to be assessed based upon variation from
the 0 m/s reading?
Interpretation:
Some of the performance tests are intended to be an accuracy based assessment from the
applied gas concentration (eg. Short Term Stability and Calibration Curve). Other
performance tests are intended to be a variation based assessment from a known baseline
(eg. Baseline at 20 °C for Temperature test and baseline at 100 kPa for Pressure test).
ICS 29.260.20
– 2 – IEC 60079-29-1:2016/ISH1:2019
 IEC 2019
In review of the air velocity acceptance criteria, the format is the same as the Short Term
Stability and Calibration Curve and therefore this is intended to be an accuracy based
assessment.
 IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-29-1
Edition 2.0  2016-07
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors –
Performance requirements of detectors for flammable gases

INTERPRETATION SHEET 2
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
31/1457/DISH 31/1467/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

___________
In accordance with Administrative Circular AC/42/2004: New procedures for Interpretation of
standards, Annex 2: New text for ISO/IEC Directives (IEC Supplement), there has been a
request for formal interpretation of the required testing for each general purpose test gas for
performance standard IEC 60079-29-1:2016, Subclause 5.3.2 (c), by the Australian National
Committee. The requirement is stated as follows:
c) Methane, and propane or butane for equipment intended for general purpose flammable
gas detection (in order to get representative results, e.g. concerning sensitivity, response
times and drift).
Question:
Is the interpretation of this text that propane or butane required tests are only Calibration and
adjustment (5.4.3), Short-term stability (5.4.4.2), and Time of response (5.4.15)?
ICS 29.260.20
– 2 – IEC 60079-29-1:2016/ISH2:2019
 IEC 2019
Interpretation:
No, for general purpose equipment evaluation to two gases is essential in order to get
representative test results. Therefore, all tests need to be conducted for the two gases unless
otherwise specified (e.g. EMC as outlined in IEC 60079-29-1/AMD1:— ).

____________
Under preparation. Stage at the time of publication: IEC/CCDV 60079-29-1/AMD1:2019.

– 2 – IEC 60079-29-1:2016 © IEC 2016
CONTENTS
FOREWORD . 4
INTRODUCTION . 8
1 Scope . 9
2 Normative references . 10
3 Terms and definitions . 10
4 General requirements . 15
4.1 Overview . 15
4.1.1 Manufacturer claims . 15
4.1.2 Equipment ratings . 16
4.2 Construction . 16
4.2.1 General . 16
4.2.2 Indicating devices . 16
4.2.3 Alarm signals . 18
4.2.4 Fault signals . 18
4.2.5 Adjustments . 19
4.2.6 Battery-powered equipment . 19
4.2.7 Gas detection transmitter for use with separate gas detection control
units . 19
4.2.8 Separate gas detection control units for use with gas detection
transmitter(s) . 19
4.2.9 Software-controlled equipment . 20
4.3 Marking . 21
4.4 Instruction manual . 21
5 Test methods . 23
5.1 Overview . 23
5.2 General requirements for tests . 24
5.2.1 General . 24
5.2.2 Samples and sequence of tests . 24
5.2.3 Preparation of equipment before testing . 24
5.2.4 Mask for calibration and tests . 25
5.3 Normal conditions for test . 25
5.3.1 General . 25
5.3.2 Test gas(es) . 25
5.3.3 Standard test gas . 26
5.3.4 Flow rate for test gases . 26
5.3.5 Voltage . 26
5.3.6 Temperature . 26
5.3.7 Pressure . 27
5.3.8 Humidity . 27
5.3.9 Acclimation time . 27
5.3.10 Orientation. 27
5.3.11 Communications options . 27
5.3.12 Gas detection equipment as part of systems . 27
5.4 Test methods . 27
5.4.1 General . 27
5.4.2 Unpowered storage . 28
5.4.3 Calibration and adjustment . 28

5.4.4 Stability . 29
5.4.5 Alarm set point(s) . 30
5.4.6 Temperature . 30
5.4.7 Pressure . 31
5.4.8 Humidity of test gas . 31
5.4.9 Air velocity . 31
5.4.10 Flow rate for aspirated equipment . 32
5.4.11 Orientation. 32
5.4.12 Vibration . 32
5.4.13 Drop test for portable and transportable equipment . 33
5.4.14 Warm-up time . 33
5.4.15 Time of response . 34
5.4.16 High gas concentration operation above the measuring range . 34
5.4.17 Battery capacity . 34
5.4.18 Power supply variations . 35
5.4.19 Addition of sampling probe . 35
5.4.20 Other gases and poisons . 35
5.4.21 Electromagnetic compatibility . 36
5.4.22 Field calibration kit . 36
5.4.23 Software function . 36
Annex A (normative) Performance requirements . 37
Annex B (informative) Determination of time of response . 43
B.1 Aspirated equipment . 43
B.1.1 Test rig . 43
B.1.2 Equipment without internal pump . 43
B.1.3 Equipment with internal pump . 43
B.2 Equipment that samples by diffusion . 44
B.2.1 Calibration mask method . 44
B.2.2 Diffusion or flow methods . 44
Bibliography . 45

Figure 1 – Warm-up time in clean air (typical) . 15
Figure 2 – Warm-up time in standard test gas (typical) . 15
Figure B.1 – Schematic example of test rig for use with aspirated equipment . 44

Table A.1 – Performance requirements (1 of 6) . 37

– 4 – IEC 60079-29-1:2016 © IEC 2016
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors – Performance requirements
of detectors for flammable gases

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60079-29-1 has been prepared by IEC technical committee 31:
Equipment for explosive atmospheres.
This second edition of IEC 60079-29-1 cancels and replaces the first edition of
IEC 60079-29-1:2007 series and constitutes a technical revision.
The contents of the interpretation sheets 1 and 2 (2019-04) have been included in this copy.
Significant technical changes between IEC 60079-29-1, Edition 1 (2007), and
IEC 60079-29-1, Edition 2 (2016), is as listed below:
Significant changes with respect to IEC 60079-29-1:2007

Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Measuring range up to 20 % LEL All X
(Modified requirements)
Definitions 3 X
(Additional clarifications)
Manufacturer’s claims 4.1.1 X
(special applications requirements)
General construction 4.2.1  C1
(Malfunction effects on safety related function)
General indicating devices 4.2.2.1  C2
(portable equipment with visual and audible indication)
Suppression of indication and measured values below zero 4.2.2.5  C3
(functional limits)
Fault signals 4.2.4  C4
(Fault indication below minimum voltage limit, sensor
disconnection and zero drift condition)
Adjustments 4.2.5  C5
(Zero and sensitivity adjustments)
Marking 4.3 X
(Portable equipment protective case)
Instruction Manual 4.4  C6
(Additions and clarifications)
Samples and sequence of tests 5.2.2 X
(Optical filter special sensitivity limits, and modification
considerations)
Preparation of equipment before testing 5.2.3 X
(separate gas detection control units)
Test gas 5.3.2  C7
(methane, and propane or butane for general purpose gas
detector)
General test methods 5.4.1 X
(selectable range and wiring worst case conditions)
Calibration curve 5.4.3.2  C8
(fixed volume fractions)
Response to different gases 5.4.3.3  C9
(semiconductor and catalytic high gas concentration
exposure)
Stability 5.4.4 X
(duration of test method)
Alarm set point(s) 5.4.5 X
(alarm set point test method)
Temperature (portable) 5.4.6  C10
(temperature range and stabilization period)
Temperature (all other equipment) 5.4.6 X
(temperature range and stabilization period)
Pressure 5.4.7 X
(tolerance on pressure measurement)
Humidity of test gas 5.4.8 X
(test method clarification)
Air velocity 5.4.9 X
(test method clarification)
Flow rate for aspirated equipment 5.4.10 X
(test method clarification)
Vibration 5.4.12 X
(test method clarification)
– 6 – IEC 60079-29-1:2016 © IEC 2016
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Drop test for portable and transportable equipment 5.4.13 X
(Automatic re-starting or shut-down requirement
clarification)
Warm-up time 5.4.14  C11
(user prompt requirement)
High gas concentration operation above the measuring 5.4.16 X
range
(test method and requirement clarification)
Battery capacity 5.4.17 X
(test method clarification)
Power supply variation 5.4.18  C12
(minimum supply voltage fault limit)
Poisons (applicable only to Group I apparatus with catalytic 5.4.20.2 X
or semiconductor sensors)
(test method clarification)
Electromagnetic compatibility 5.4.21  C13
(test methods and requirements)
Field calibration kit 5.4.22 X
(test method clarification)
Software function 5.4.23 X
(supporting documentation)
Determination of time of response Annex B X
(test method clarification)
NOTE 1 The technical changes referred to include the significance of technical changes in the revised IEC
Standard, but they do not form an exhaustive list of all modifications from the previous version. More guidance may
be found by referring to the Redline Version of the standard.
Explanations:
A) Definitions
Minor and editorial changes
Clarification decrease of technical requirements minor technical change editorial
corrections.
These are changes which modify requirements in an editorial or a minor technical way.
They include changes of the wording to clarify technical requirements without any
technical change, or a reduction in level of existing requirement.
Extension
Addition of technical options
These are changes which add new or modify existing technical requirements, in a way that
new options are given, but without increasing requirements for equipment that was fully
compliant with the previous standard. Therefore, these will not have to be considered for
products in conformity with the preceding edition.
Major technical changes
Addition of technical requirements increase of technical requirements.
These are changes to technical requirements (addition, increase of the level or removal)
made in a way that a product conforming to the preceding edition will not always be able
to fulfil the requirements given in the later edition. These changes have to be considered
for products conforming to the preceding edition. For these changes additional information
is provided in B) below.
NOTE 2 These changes represent current technological knowledge. However, these changes should not
normally have an influence on equipment already placed on the market.

B) Information about the background of ‘Major technical changes’
C1 Addition of malfunction effects not adversely affecting the safety related function
(4.2.1).
C2 Addition of visual and audible indication for portable equipment (4.2.2.1).
C3 Addition of functional limits for suppression of indication and for measured values
below zero (4.2.2.5).
C4 Addition of requirements for fault indication below minimum voltage limit, sensor
disconnection and zero drift condition (4.2.4).
C5 Addition of requirements for zero and sensitivity adjustments (4.2.5).
C6 Addition and clarification requirements for inclusion within the instruction manual
(4.4).
C7 Addition of methane and propane or butane as required test gases for general
purpose gas detector (5.3.2).
C8 Specification of fixed volume fractions which are expressed as a percentage of the
measuring range (5.4.3.2).
C9 Addition of requirement for semiconductor and catalytic sensors to be exposed to
high gas concentration on response to different gases (5.4.3.3).
C10 Addition of temperature range and stabilization period (5.4.6).
C11 Addition of requirement where equipment prompts the user (5.4.14).
C12 Addition of requirement for output functionality above the minimum supply voltage
fault limit (5.4.18).
C13 Addition of test methods and requirements for electromagnetic compatibility tests
(5.4.21).
This bilingual version (2017-12) corresponds to the monolingual English version, published in
2016-07.
The text of this standard is based on the following documents:
FDIS Report on voting
31/1257/FDIS 31/1266/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
The French version of this standard has not been voted upon.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60079 series, under the general title Explosive atmospheres, can
be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 8 – IEC 60079-29-1:2016 © IEC 2016
INTRODUCTION
This part of IEC 60079-29 specifies general requirements for construction, testing and
performance, and describes the test methods that apply to portable, transportable and fixed
equipment for the detection and measurement of flammable gas or vapour concentrations with
air.
Guidance for the selection, installation, use and maintenance of gas detecting equipment is
set out in IEC 60079-29-2: Explosive atmospheres – Part 29-2: Gas detectors – Selection,
installation, use and maintenance of detectors for flammable gases and oxygen.
Guidance for functional safety of fixed gas detection systems is set out in IEC 60079-29-3:
Explosive atmospheres – Part 29-3: Gas detectors – Guidance on functional safety of fixed
gas detection systems.
General requirements for construction, testing and performance of open path detectors for
flammable gases are set out in IEC 60079-29-4: Explosive atmospheres – Part 29-4: Gas
detectors – Performance requirements of open path detectors for flammable gases.

EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors – Performance requirements
of detectors for flammable gases

1 Scope
This part of IEC 60079-29 specifies general requirements for construction, testing and
performance, and describes the test methods that apply to portable, transportable and fixed
equipment for the detection and measurement of flammable gas or vapour concentrations with
air. The equipment, or parts thereof, is intended for use in explosive atmospheres and in
mines susceptible to firedamp.
This part of IEC 60079-29 is applicable to flammable gas detection equipment with a
measuring range up to any volume fraction as declared by the manufacturer, and which is
intended to provide an indication, alarm or other output function; the purpose of which is to
indicate a potential explosion hazard and in some cases, to initiate automatic or manual
protective action(s).
For the purposes of this part of IEC 60079-29, the term “indicating up to a volume fraction of
X % or X %LFL” includes equipment with an upper limit of the measuring range equal to or
less than X % or X %LFL.
This part of IEC 60079-29 is applicable to equipment, including the integral sampling systems
of aspirated equipment, intended to be used for commercial, industrial and non-residential
safety applications.
This part of IEC 60079-29 does not apply to external sampling systems, or to equipment of
laboratory or scientific type, or to equipment used only for process monitoring and/or control
purposes. It also does not apply to open path (line of sight) detectors which are within the
scope of IEC 60079-29-4. Only equipment with very short optical paths intended for use
where the concentration is uniform over the optical path are within the scope of this standard.
For equipment used for sensing the presence of multiple gases, this part of IEC 60079-29
applies only to the detection of flammable gas or vapour.
This part of IEC 60079-29 supplements and modifies the general requirements of
IEC 60079-0. Where a requirement of this standard conflicts with a requirement of
IEC 60079-0, the requirement of IEC 60079-29-1 takes precedence.
NOTE 1 IEC 60079-29-1 is intended to provide for the supply of equipment giving a level of safety and
performance suitable for general purpose applications. However, for specific applications, a prospective purchaser
(or an appropriate authority) can additionally require the equipment to be submitted to particular tests or approval.
For example, Group I equipment (i.e. equipment to be used in mines susceptible to firedamp) might not be
permitted to be used without the additional, prior approval of the relevant authority in mines under its jurisdiction.
Such particular tests/approval are to be regarded as additional to and separate from the provisions of the
standards referred to above and do not preclude certification to or compliance with these standards.
NOTE 2 All equipment calibrated on specific gases or vapours can not be expected to correctly indicate on other
gases or vapours.
For the purposes of this standard, the terms "lower flammable limit (LFL)" and "lower
explosive limit (LEL)" are deemed to be synonymous, and likewise the terms "upper
flammable limit (UFL)" and "upper explosive limit (UEL)" are deemed to be synonymous. For
ease of reference, the two abbreviations LFL and UFL may be used hereinafter to denote
these two sets of terms. It should be recognized that particular authorities having jurisdiction
may have overriding requirements that dictate the use of one of these sets of terms and not
the other.
– 10 – IEC 60079-29-1:2016 © IEC 2016
NOTE 3 Indication of concentration in %(v/v) or vol ppm can also be available for equipment which measures up
to 100 %LFL or 20 %LFL. In that case, units of measurement might need to be selected in agreement with the
manufacturer when verifying the performance requirements of Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-426, International Electrotechnical Vocabulary – Part 426: Equipment for explosive
atmospheres
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60079-20-1, Explosive atmospheres – Part 20-1: Material characteristics for gas and
vapour classification – Test methods and data
IEC 61326-1:2012, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60079-0 and the
following apply. Additional definitions applicable to explosive atmospheres can be found in
IEC 60050-426.
3.1
gas properties
3.1.1
ambient air
normal atmosphere surrounding the equipment
3.1.2
clean air
air that is free of gases or vapours which the sensor is sensitive to or which influence the
performance of the sensor
3.1.3
flammable gas
gas or vapour which, when mixed with air in a certain proportion, will form an explosive
atmosphere
Note 1 to entry: For the purposes of this part of IEC 60079-29, the term "flammable gas" includes flammable
vapours.
Note 2 to entry: For the purposes of this part of IEC 60079-29, the terms "combustible gas" and "flammable gas"
are equivalent.
3.1.4
lower flammable limit
LFL
concentration of flammable gas or vapour in air, below which an explosive gas atmosphere
does not form
Note 1 to entry: This is also known as lower explosive limit (LEL).

Note 2 to entry: The concentration may be expressed as either a volume fraction or a mass per unit volume.
3.1.5
poisons
substances that lead to temporary or permanent change of
performance, particularly loss of sensitivity of the sensing element
3.1.6
upper flammable limit
UFL
concentration of of flammable gas or vapour in air, above which an explosive gas atmosphere
does not form
Note 1 to entry: This is also known as upper explosive limit (UEL).
Note 2 to entry: The concentration may be expressed as either a volume fraction or a mass per unit volume.
3.1.7
volume fraction
v/v
quotient of the volume of a specified component and the sum of the volumes of all
components of a gas mixture before mixing, all volumes referring to the pressure and the
temperature of the gas mixture
Note 1 to entry: The volume fraction and volume concentration take the same value if, at the same state
conditions, the sum of the component volumes before mixing and the volume of the mixture are equal. However,
because the mixing of two or more gases at the same state conditions is usually accompanied by a slight
contraction or, less frequently, a slight expansion, this is not generally the case.
3.1.8
zero gas
gas recommended by the manufacturer, which is free of flammable gases and interfering and
contaminating substances, the purpose of which is calibration/adjustment of the equipment
zero
3.1.9
standard test gas
test gas with a composition specified for each item of equipment and gas and/or vapour to be
used for all tests unless otherwise stated
3.2
types of equipment
3.2.1
alarm-only equipment
equipment with an alarm but not having an indication of measured value
3.2.2
aspirated equipment
equipment that samples the gas by drawing it to the gas sensor
Note 1 to entry: A hand operated or electric pump is often used to draw gas to the sensor.
3.2.3
automatically aspirated equipment
aspirated equipment with an integral pump or separate pump, which is connected directly to
the equipment
3.2.4
continuous duty equipment
equipment that is powered for long periods of time, but may have either continuous or
intermittent sensing
– 12 – IEC 60079-29-1:2016 © IEC 2016
Note 1 to entry: For this edition of the standard, all equipment is regarded as continuous duty.
3.2.5
diffusion equipment
equipment in which the transfer of gas from the atmosphere to the sensor takes place without
aspirated flow
3.2.6
equipment, fixed
equipment fastened to a support, or otherwise secured in a specific location when energized
3.2.7
Group I equipment
equipment for mines susceptible to firedamp
3.2.8
Group II equipment
equipment for places with an explosive gas atmosphere, other than mines susceptible to
firedamp
3.2.9
equipment, portable
equipment intended to be carried by a person during operation
Note 1 to entry: A portable equipment is battery powered and includes, but is not limited to
a) a hand-held equipment, typically less than 1 kg, which requires use of only one hand to operate,
b) personal monitors, similar in size and mass to the hand-held equipment, that are continuously operating (but
not necessarily continuously sensing) while they are attached to the user, and
c) larger equipment that can be operated by the user while it is carried either by hand, by a shoulder strap or
carrying harness and which may or may not have a hand directed probe.
3.2.10
equipment, transportable
equipment not intended to be carried by a person during operation, nor intended for fixed
installation
3.2.11
gas detection transmitter
fixed gas detection equipment that provide a conditioned electronic signal or output indication
to a generally accepted industry standard (such as 4 to 20 mA), intended to be utilized with
separate gas detection control units or signal processing data acquisition, central monitoring
and similar systems, which typically process information from various locations and sources
including, but not limited to gas detection equipment
3.2.12
gas detection control unit
equipment intended to provide display indication, alarm functions, output contacts and/or
alarm signal outputs or any combinations when operated with remote sensor(s)
3.2.13
separate gas detection control unit
equipment intended to provide display indication, alarm functions, output contacts or alarm
signal outputs or any combination when operated with gas detection transmitter(s)
3.2.14
equipment with integral sensor(s)
equipment that provides display indication, alarm functions, output contacts and/or alarm
signal outputs using a sensor which is within or directly mounted to the equipment housing

3.2.15
accessory
component which can be fitted to the equipment for special purpose
EXAMPLE External gas pump, sampling probe, hoses, collecting cone, weather protection device
3.3
sensors
3.3.1
sensing element
part of the sensor which is sensitive to the gas/vapour to be measured
3.3.2
sensor
assembly in which the sensing element is housed and that may also contain associated circuit
components
3.3.3
integral sensor
sensor which is within or directly mounted to the equipment housing
3.3.4
remote sensor
sensor that is separated from the equipment body and is connected to a gas detection control
unit or to a gas detection transmitter.
3.4
supply of gas to equipment
3.4.1
sample line
means by which the gas being sampled is conveyed to the sensor
Note 1 to entry: Accessories such as filter or water trap are often included in
...

IEC 60079-29-1 ®
Edition 2.1 2020-03
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 29-1: Gas detectors – Performance requirements of detectors for flammable
gases
Atmosphères explosives –
Partie 29-1: Détecteurs de gaz – Exigences d’aptitude à la fonction des
détecteurs de gaz inflammables

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IEC 60079-29-1 ®
Edition 2.1 2020-03
CONSOLIDATED VERSION
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Explosive atmospheres –
Part 29-1: Gas detectors – Performance requirements of detectors for flammable

gases
Atmosphères explosives –
Partie 29-1: Détecteurs de gaz – Exigences d’aptitude à la fonction des

détecteurs de gaz inflammables

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 29.260.20 ISBN 978-2-8322-8063-8

IEC 60079-29-1 ®
Edition 2.1 2020-03
CONSOLIDATED VERSION
REDLINE VERSION
VERSION REDLINE
colour
inside
Explosive atmospheres –
Part 29-1: Gas detectors – Performance requirements of detectors for flammable
gases
Atmosphères explosives –
Partie 29-1: Détecteurs de gaz – Exigences d’aptitude à la fonction des
détecteurs de gaz inflammables

 IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-29-1
Edition 2.0  2016-07
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors –
Performance requirements of detectors for flammable gases

INTERPRETATION SHEET 1
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
31/1456/DISH 31/1462/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

___________
In accordance with Administrative Circular AC/42/2004: New procedures for interpretation of
standards, Annex 2: New text for ISO/IEC Directives (IEC Supplement), there has been a
request for formal interpretation of the Air Velocity test acceptance criterion in the
performance standard IEC 60079-29-1:2016.
Question:
Is the acceptance criteria for the Air Velocity test to be assessed based upon variation from
the 0 m/s reading?
Interpretation:
Some of the performance tests are intended to be an accuracy based assessment from the
applied gas concentration (eg. Short Term Stability and Calibration Curve). Other
performance tests are intended to be a variation based assessment from a known baseline
(eg. Baseline at 20 °C for Temperature test and baseline at 100 kPa for Pressure test).
ICS 29.260.20
– 2 – IEC 60079-29-1:2016/ISH2:2019
 IEC 2019
Interpretation:
No, for general purpose equipment evaluation to two gases is essential in order to get
representative test results. Therefore, all tests need to be conducted for the two gases unless
otherwise specified (e.g. EMC as outlined in IEC 60079-29-1/AMD1:— ).

____________
Under preparation. Stage at the time of publication: IEC/CCDV 60079-29-1/AMD1:2019.

 IEC 2019
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
IEC 60079-29-1
Edition 2.0  2016-07
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors –
Performance requirements of detectors for flammable gases

INTERPRETATION SHEET 2
This interpretation sheet has been prepared by IEC technical committee 31: Equipment for
explosive atmospheres.
The text of this interpretation sheet is based on the following documents:
DISH Report on voting
31/1457/DISH 31/1467/RVDISH
Full information on the voting for the approval of this interpretation sheet can be found in the
report on voting indicated in the above table.

___________
In accordance with Administrative Circular AC/42/2004: New procedures for Interpretation of
standards, Annex 2: New text for ISO/IEC Directives (IEC Supplement), there has been a
request for formal interpretation of the required testing for each general purpose test gas for
performance standard IEC 60079-29-1:2016, Subclause 5.3.2 (c), by the Australian National
Committee. The requirement is stated as follows:
c) Methane, and propane or butane for equipment intended for general purpose flammable
gas detection (in order to get representative results, e.g. concerning sensitivity, response
times and drift).
Question:
Is the interpretation of this text that propane or butane required tests are only Calibration and
adjustment (5.4.3), Short-term stability (5.4.4.2), and Time of response (5.4.15)?
ICS 29.260.20
– 2 – IEC 60079-29-1:2016/ISH1:2019
 IEC 2019
In review of the air velocity acceptance criteria, the format is the same as the Short Term
Stability and Calibration Curve and therefore this is intended to be an accuracy based
assessment.
– 2 – IEC 60079-29-1:2016+AMD1:2020 CSV
© IEC 2020
CONTENTS
FOREWORD . 4
INTRODUCTION . 9
1 Scope . 10
2 Normative references . 11
3 Terms and definitions . 11
4 General requirements . 16
4.1 Overview . 16
4.1.1 Manufacturer claims . 16
4.1.2 Equipment ratings . 17
4.2 Construction . 17
4.2.1 General . 17
4.2.2 Indicating devices . 17
4.2.3 Alarm signals . 19
4.2.4 Fault signals . 19
4.2.5 Adjustments . 20
4.2.6 Battery-powered equipment . 20
4.2.7 Gas detection transmitter for use with separate gas detection control
units . 20
4.2.8 Separate gas detection control units for use with gas detection
transmitter(s) . 20
4.2.9 Software-controlled equipment . 21
4.3 Marking . 22
4.4 Instruction manual . 22
5 Test methods . 24
5.1 Overview . 24
5.2 General requirements for tests . 25
5.2.1 General . 25
5.2.2 Samples and sequence of tests . 25
5.2.3 Preparation of equipment before testing . 26
5.2.4 Mask for calibration and tests . 26
5.3 Normal conditions for test . 27
5.3.1 General . 27
5.3.2 Test gas(es) . 27
5.3.3 Standard test gas . 27
5.3.4 Flow rate for test gases . 27
5.3.5 Voltage . 28
5.3.6 Temperature . 28
5.3.7 Pressure . 28
5.3.8 Humidity . 28
5.3.9 Acclimation time . 28
5.3.10 Orientation. 28
5.3.11 Communications options . 28
5.3.12 Gas detection equipment as part of systems . 28
5.4 Test methods . 29
5.4.1 General . 29
5.4.2 Unpowered storage . 29

© IEC 2020
5.4.3 Calibration and adjustment . 29
5.4.4 Stability . 30
5.4.5 Alarm set point(s) . 31
5.4.6 Temperature . 32
5.4.7 Pressure . 32
5.4.8 Humidity of test gas . 32
5.4.9 Air velocity . 32
5.4.10 Flow rate for aspirated equipment . 33
5.4.11 Orientation. 33
5.4.12 Vibration . 33
5.4.13 Drop test for portable and transportable equipment . 34
5.4.14 Warm-up time . 35
5.4.15 Time of response . 35
5.4.16 High gas concentration operation above the measuring range . 35
5.4.17 Battery capacity . 35
5.4.18 Power supply variations . 36
5.4.19 Addition of sampling probe . 36
5.4.20 Other gases and poisons . 36
5.4.21 Electromagnetic compatibility . 37
5.4.22 Field calibration kit . 38
5.4.23 Software function . 38
Annex A (normative) Performance requirements . 39
Annex B (informative) Determination of time of response . 45
B.1 Aspirated equipment . 45
B.1.1 Test rig . 45
B.1.2 Equipment without internal pump . 45
B.1.3 Equipment with internal pump . 45
B.2 Equipment that samples by diffusion . 46
B.2.1 Calibration mask method . 46
B.2.2 Diffusion or flow methods . 46
Bibliography . 47

Figure 1 – Warm-up time in clean air (typical) . 16
Figure 2 – Warm-up time in standard test gas (typical) . 16
Figure B.1 – Schematic example of test rig for use with aspirated equipment . 46

Table A.1 – Performance requirements (1 of 6) . 39

– 4 – IEC 60079-29-1:2016+AMD1:2020 CSV
© IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors – Performance requirements
of detectors for flammable gases

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
This consolidated version of the official IEC Standard and its amendment has been
prepared for user convenience.
IEC 60079-29-1 edition 2.1 contains the second edition (2016-07) [documents
31/1257/FDIS and 31/1266/RVD], the contents of the interpretation sheets 1 and 2 (2019-
04), and its amendment 1 (2020-03) [documents 31/1525/FDIS and 31/1533/RVD].
In this Redline version, a vertical line in the margin shows where the technical content
is modified by amendment 1. Additions are in green text, deletions are in strikethrough
red text. A separate Final version with all changes accepted is available in this
publication.
© IEC 2020
International Standard IEC 60079-29-1 has been prepared by IEC technical committee 31:
Equipment for explosive atmospheres.
This second edition of IEC 60079-29-1 constitutes a technical revision.
Significant technical changes between IEC 60079-29-1, Edition 1 (2007), and
IEC 60079-29-1, Edition 2 (2016), is as listed below:
Significant changes with respect to IEC 60079-29-1:2007:
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Measuring range up to 20 % LEL All X
(Modified requirements)
Definitions 3 X
(Additional clarifications)
Manufacturer’s claims 4.1.1 X
(special applications requirements)
General construction 4.2.1  C1
(Malfunction effects on safety related function)
General indicating devices 4.2.2.1  C2
(portable equipment with visual and audible indication)
Suppression of indication and measured values below zero 4.2.2.5  C3
(functional limits)
Fault signals 4.2.4  C4
(Fault indication below minimum voltage limit, sensor
disconnection and zero drift condition)
Adjustments 4.2.5  C5
(Zero and sensitivity adjustments)
Marking 4.3 X
(Portable equipment protective case)
Instruction Manual 4.4  C6
(Additions and clarifications)
Samples and sequence of tests
5.2.2 X
(Optical filter special sensitivity limits, and modification
considerations)
Preparation of equipment before testing 5.2.3 X
(separate gas detection control units)
Test gas 5.3.2  C7
(methane, and propane or butane for general purpose gas
detector)
General test methods 5.4.1 X
(selectable range and wiring worst case conditions)
Calibration curve 5.4.3.2  C8
(fixed volume fractions)
Response to different gases 5.4.3.3  C9
(semiconductor and catalytic high gas concentration
exposure)
Stability
5.4.4 X
(duration of test method)
Alarm set point(s) 5.4.5 X
(alarm set point test method)
Temperature (portable) 5.4.6  C10
(temperature range and stabilization period)
Temperature (all other equipment) 5.4.6 X
(temperature range and stabilization period)

– 6 – IEC 60079-29-1:2016+AMD1:2020 CSV
© IEC 2020
Type
Changes Clause Minor and Extension Major
editorial technical
changes changes
Pressure 5.4.7 X
(tolerance on pressure measurement)
Humidity of test gas 5.4.8 X
(test method clarification)
Air velocity 5.4.9 X
(test method clarification)
Flow rate for aspirated equipment 5.4.10 X
(test method clarification)
Vibration 5.4.12 X
(test method clarification)
Drop test for portable and transportable equipment 5.4.13 X
(Automatic re-starting or shut-down requirement
clarification)
Warm-up time 5.4.14  C11
(user prompt requirement)
High gas concentration operation above the measuring 5.4.16 X
range
(test method and requirement clarification)
Battery capacity 5.4.17 X
(test method clarification)
Power supply variation 5.4.18  C12
(minimum supply voltage fault limit)
Poisons (applicable only to Group I apparatus with catalytic 5.4.20.2 X
or semiconductor sensors)
(test method clarification)
Electromagnetic compatibility 5.4.21  C13
(test methods and requirements)
Field calibration kit 5.4.22 X
(test method clarification)
Software function 5.4.23 X
(supporting documentation)
Determination of time of response
Annex B X
(test method clarification)
NOTE 1 The technical changes referred to include the significance of technical changes in the revised IEC
Standard, but they do not form an exhaustive list of all modifications from the previous version. More guidance may
be found by referring to the Redline Version of the standard.
Explanations:
A) Definitions
Minor and editorial changes
Clarification decrease of technical requirements minor technical change editorial
corrections.
These are changes which modify requirements in an editorial or a minor technical way.
They include changes of the wording to clarify technical requirements without any
technical change, or a reduction in level of existing requirement.
Extension
Addition of technical options
These are changes which add new or modify existing technical requirements, in a way that
new options are given, but without increasing requirements for equipment that was fully
compliant with the previous standard. Therefore, these will not have to be considered for
products in conformity with the preceding edition.

© IEC 2020
Major technical changes
Addition of technical requirements increase of technical requirements.
These are changes to technical requirements (addition, increase of the level or removal)
made in a way that a product conforming to the preceding edition will not always be able
to fulfil the requirements given in the later edition. These changes have to be considered
for products conforming to the preceding edition. For these changes additional information
is provided in B) below.
NOTE 2 These changes represent current technological knowledge. However, these changes should not
normally have an influence on equipment already placed on the market.
B) Information about the background of ‘Major technical changes’
C1 Addition of malfunction effects not adversely affecting the safety related function
(4.2.1).
C2 Addition of visual and audible indication for portable equipment (4.2.2.1).
C3 Addition of functional limits for suppression of indication and for measured values
below zero (4.2.2.5).
C4 Addition of requirements for fault indication below minimum voltage limit, sensor
disconnection and zero drift condition (4.2.4).
C5 Addition of requirements for zero and sensitivity adjustments (4.2.5).
C6 Addition and clarification requirements for inclusion within the instruction manual
(4.4).
C7 Addition of methane and propane or butane as required test gases for general
purpose gas detector (5.3.2).
C8 Specification of fixed volume fractions which are expressed as a percentage of the
measuring range (5.4.3.2).
C9 Addition of requirement for semiconductor and catalytic sensors to be exposed to
high gas concentration on response to different gases (5.4.3.3).
C10 Addition of temperature range and stabilization period (5.4.6).
C11 Addition of requirement where equipment prompts the user (5.4.14).
C12 Addition of requirement for output functionality above the minimum supply voltage
fault limit (5.4.18).
C13 Addition of test methods and requirements for electromagnetic compatibility tests
(5.4.21).
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all parts of the IEC 60079 series, under the general title Explosive atmospheres, can
be found on the IEC website.
– 8 – IEC 60079-29-1:2016+AMD1:2020 CSV
© IEC 2020
The committee has decided that the contents of the base publication and its amendment will
remain unchanged until the stability date indicated on the IEC web site under
"http://webstore.iec.ch" in the data related to the specific publication. At this date, the
publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct
understanding of its contents. Users should therefore print this document using a
colour printer.
© IEC 2020
INTRODUCTION
This part of IEC 60079-29 specifies general requirements for construction, testing and
performance, and describes the test methods that apply to portable, transportable and fixed
equipment for the detection and measurement of flammable gas or vapour concentrations with
air.
Guidance for the selection, installation, use and maintenance of gas detecting equipment is
set out in IEC 60079-29-2: Explosive atmospheres – Part 29-2: Gas detectors – Selection,
installation, use and maintenance of detectors for flammable gases and oxygen.
Guidance for functional safety of fixed gas detection systems is set out in IEC 60079-29-3:
Explosive atmospheres – Part 29-3: Gas detectors – Guidance on functional safety of fixed
gas detection systems.
General requirements for construction, testing and performance of open path detectors for
flammable gases are set out in IEC 60079-29-4: Explosive atmospheres – Part 29-4: Gas
detectors – Performance requirements of open path detectors for flammable gases.

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EXPLOSIVE ATMOSPHERES –
Part 29-1: Gas detectors – Performance requirements
of detectors for flammable gases

1 Scope
This part of IEC 60079-29 specifies general requirements for construction, testing and
performance, and describes the test methods that apply to portable, transportable and fixed
equipment for the detection and measurement of flammable gas or vapour concentrations with
air. The equipment, or parts thereof, is intended for use in explosive atmospheres and in
mines susceptible to firedamp.
This part of IEC 60079-29 is applicable to flammable gas detection equipment with a
measuring range up to any volume fraction as declared by the manufacturer, and which is
intended to provide an indication, alarm or other output function; the purpose of which is to
indicate a potential explosion hazard and in some cases, to initiate automatic or manual
protective action(s).
For the purposes of this part of IEC 60079-29, the term “indicating up to a volume fraction of
X % or X %LFL” includes equipment with an upper limit of the measuring range equal to or
less than X % or X %LFL.
This part of IEC 60079-29 is applicable to equipment, including the integral sampling systems
of aspirated equipment, intended to be used for commercial, industrial and non-residential
safety applications.
This part of IEC 60079-29 does not apply to external sampling systems, or to equipment of
laboratory or scientific type, or to equipment used only for process monitoring and/or control
purposes. It also does not apply to open path (line of sight) detectors which are within the
scope of IEC 60079-29-4. Only equipment with very short optical paths intended for use
where the concentration is uniform over the optical path are within the scope of this standard.
For equipment used for sensing the presence of multiple gases, this part of IEC 60079-29
applies only to the detection of flammable gas or vapour.
This part of IEC 60079-29 supplements and modifies the general requirements of
IEC 60079-0. Where a requirement of this standard conflicts with a requirement of
IEC 60079-0, the requirement of IEC 60079-29-1 takes precedence.
NOTE 1 IEC 60079-29-1 is intended to provide for the supply of equipment giving a level of safety and
performance suitable for general purpose applications. However, for specific applications, a prospective purchaser
(or an appropriate authority) can additionally require the equipment to be submitted to particular tests or approval.
For example, Group I equipment (i.e. equipment to be used in mines susceptible to firedamp) might not be
permitted to be used without the additional, prior approval of the relevant authority in mines under its jurisdiction.
Such particular tests/approval are to be regarded as additional to and separate from the provisions of the
standards referred to above and do not preclude certification to or compliance with these standards.
NOTE 2 All equipment calibrated on specific gases or vapours can not be expected to correctly indicate on other
gases or vapours.
For the purposes of this standard, the terms "lower flammable limit (LFL)" and "lower
explosive limit (LEL)" are deemed to be synonymous, and likewise the terms "upper
flammable limit (UFL)" and "upper explosive limit (UEL)" are deemed to be synonymous. For
ease of reference, the two abbreviations LFL and UFL may be used hereinafter to denote
these two sets of terms. It should be recognized that particular authorities having jurisdiction
may have overriding requirements that dictate the use of one of these sets of terms and not
the other.
© IEC 2020
NOTE 3 Indication of concentration in %(v/v) or vol ppm can also be available for equipment which measures up
to 100 %LFL or 20 %LFL. In that case, units of measurement might need to be selected in agreement with the
manufacturer when verifying the performance requirements of Annex A.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-426, International Electrotechnical Vocabulary – Part 426: Equipment for explosive
atmospheres
IEC 60079-0, Explosive atmospheres – Part 0: Equipment – General requirements
IEC 60068-2-6, Environmental testing – Part 2-6: Tests – Test Fc: Vibration (sinusoidal)
IEC 60079-20-1, Explosive atmospheres – Part 20-1: Material characteristics for gas and
vapour classification – Test methods and data
IEC 61326-1:2012, Electrical equipment for measurement, control and laboratory use – EMC
requirements – Part 1: General requirements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60079-0 and the
following apply. Additional definitions applicable to explosive atmospheres can be found in
IEC 60050-426.
3.1
gas properties
3.1.1
ambient air
normal atmosphere surrounding the equipment
3.1.2
clean air
air that is free of gases or vapours which the sensor is sensitive to or which influence the
performance of the sensor
3.1.3
flammable gas
gas or vapour which, when mixed with air in a certain proportion, will form an explosive
atmosphere
Note 1 to entry: For the purposes of this part of IEC 60079-29, the term "flammable gas" includes flammable
vapours.
Note 2 to entry: For the purposes of this part of IEC 60079-29, the terms "combustible gas" and "flammable gas"
are equivalent.
3.1.4
lower flammable limit
LFL
concentration of flammable gas or vapour in air, below which an explosive gas atmosphere
does not form
Note 1 to entry: This is also known as lower explosive limit (LEL).

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Note 2 to entry: The concentration may be expressed as either a volume fraction or a mass per unit volume.
3.1.5
poisons
substances that lead to temporary or permanent change of
performance, particularly loss of sensitivity of the sensing element
3.1.6
upper flammable limit
UFL
concentration of of flammable gas or vapour in air, above which an explosive gas atmosphere
does not form
Note 1 to entry: This is also known as upper explosive limit (UEL).
Note 2 to entry: The concentration may be expressed as either a volume fraction or a mass per unit volume.
3.1.7
volume fraction
v/v
quotient of the volume of a specified component and the sum of the volumes of all
components of a gas mixture before mixing, all volumes referring to the pressure and the
temperature of the gas mixture
Note 1 to entry: The volume fraction and volume concentration take the same value if, at the same state
conditions, the sum of the component volumes before mixing and the volume of the mixture are equal. However,
because the mixing of two or more gases at the same state conditions is usually accompanied by a slight
contraction or, less frequently, a slight expansion, this is not generally the case.
3.1.8
zero gas
gas recommended by the manufacturer, which is free of flammable gases and interfering and
contaminating substances, the purpose of which is calibration/adjustment of the equipment
zero
3.1.9
standard test gas
test gas with a composition specified for each item of equipment and gas and/or vapour to be
used for all tests unless otherwise stated
3.2
types of equipment
3.2.1
alarm-only equipment
equipment with an alarm but not having an indication of measured value
3.2.2
aspirated equipment
equipment that samples the gas by drawing it to the gas sensor
Note 1 to entry: A hand operated or electric pump is often used to draw gas to the sensor.
3.2.3
automatically aspirated equipment
aspirated equipment with an integral pump or separate pump, which is connected directly to
the equipment
3.2.4
continuous duty equipment
equipment that is powered for long periods of time, but may have either continuous or
intermittent sensing
© IEC 2020
Note 1 to entry: For this edition of the standard, all equipment is regarded as continuous duty.
3.2.5
diffusion equipment
equipment in which the transfer of gas from the atmosphere to the sensor takes place without
aspirated flow
3.2.6
equipment, fixed
equipment fastened to a support, or otherwise secured in a specific location when energized
3.2.7
Group I equipment
equipment for mines susceptible to firedamp
3.2.8
Group II equipment
equipment for places with an explosive gas atmosphere, other than mines susceptible to
firedamp
3.2.9
equipment, portable
equipment intended to be carried by a person during operation
Note 1 to entry: A portable equipment is battery powered and includes, but is not limited to
a) a hand-held equipment, typically less than 1 kg, which requires use of only one hand to operate,
b) personal monitors, similar in size and mass to the hand-held equipment, that are continuously operating (but
not necessarily continuously sensing) while they are attached to the user, and
c) larger equipment that can be operated by the user while it is carried either by hand, by a shoulder strap or
carrying harness and which may or may not have a hand directed probe.
3.2.10
equipment, transportable
equipment not intended to be carried by a person during operation, nor intended for fixed
installation
3.2.11
gas detection transmitter
fixed gas detection equipment that provide a conditioned electronic signal or output indication
to a generally accepted industry standard (such as 4 to 20 mA), intended to be utilized with
separate gas detection control units or signal processing data acquisition, central monitoring
and similar systems, which typically process information from various locations and sources
including, but not limited to gas detection equipment
3.2.12
gas detection control unit
equipment intended to provide display indication, alarm functions, output contacts and/or
alarm signal outputs or any combinations when operated with remote sensor(s)
3.2.13
separate gas detection control unit
equipment intended to provide display indication, alarm functions, output contacts or alarm
signal outputs or any combination when operated with gas detection transmitter(s)
3.2.14
equipment with integral sensor(s)
equipment that provides display indication, alarm functions, output contacts and/or alarm
signal outputs using a sensor which is within or directly mounted to the equipment housing

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3.2.15
accessory
component which can be fitted to the equipment for special purpose
EXAMPLE External gas pump, sampling probe, hoses, collecting cone, weather protection device
3.3
sensors
3.3.1
sensing element
part of the
...