1 This part of IEC 61779 specifies general requirements for construction and testing and describes the test methods that apply to portable, transportable and fixed apparatus for the detection and measurement of flammable gas or vapour concentrations with air. The apparatus, or parts thereof, are intended for use in potentially explosive atmospheres (see 2.1.8) and in mines susceptible to firedamp. This standard is supplemented by the following standards, concerning the specific requirements for the performance of the various types of apparatus:
IEC 61779-2: Performance requirements for group I apparatus indicating up to a volume fraction of 5 % methane in air
IEC 61779-3: Performance requirements for group I apparatus indicating up to a volume fraction of 100 % methane in air
IEC 61779-4: Performance requirements for group II apparatus indicating up to a volume fraction of 100 % lower explosive limit
IEC 61779-5: Performance requirements for group II apparatus indicating up to a volume fraction of 100 % gas
Note deleted
NOTE 1 - Group I and group II apparatus indicating up to a volume fraction of 100 % methane and group II apparatus indicating up to a volume fraction of 100 % gas are suitable for use only with the specific gases for which they have been calibrated.
NOTE 2 - For the purpose 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.
2 This standard is applicable when an apparatus manufacturer makes any claims regarding any special features of construction or superior performance that exceed these minimum requirements. All such claims shall be verified and the test procedures shall be extended or supplemented, where necessary, to verify the claimed performance. The additional tests shall be agreed between the manufacturer and test laboratory.
3 This standard is applicable to flammable gas detection apparatus intended to provide an indication, alarm or other output function, the purpose of which is to give a warning of a potential explosion hazard and, in some cases, to initiate automatic or manual protective action(s).
4 This standard is applicable to apparatus, including the integral sampling systems of aspirated apparatus, intended to be used for commercial and industrial safety applications.
5 This standard does not apply to external sampling systems, or to apparatus of laboratory or scientific type, or to apparatus used only for process control purposes.
BS EN 61779-1:2000 history
2017BS EN 60079-29-1:2016 Explosive atmospheres. Gas detectors. Performance requirements of detectors for flammable gases
2008BS EN 60079-29-1:2007 Explosive atmospheres - Part 29-1: Gas detectors — Performance requirements of detectors for flammable gases
2000BS EN 61779-1:2000 Electrical apparatus for the detection and measurement of flammable gases - General requirements and test methods