IEC 61779-2:1998 pdf download – Electrical apparatus for the detectionand measurement of flammable gases -Part 2: Performance requirements for group apparatus indicating a volume fraction up to 5% methane in air

IEC 61779-2:1998 pdf download – Electrical apparatus for the detectionand measurement of flammable gases -Part 2: Performance requirements for group apparatus indicating a volume fraction up to 5% methane in air.
1.1 This part of IEC 61779 specifies requirements for group I (as defined in part 1) portable, transportable and fixed apparatus for the detection and measurement of methane concentrations in mine air. The apparatus, or parts thereof, are intended for use in mines susceptible to firedamp. The requirements and test methods applicable to the apparatus covered by this standard are specified in part 1.
NOTE — The use of group I apparatus may nol be permitted without the additional and prior approval of the relevant authority in mines under its jurisdiction, see note 1 of 1.1.1 of part 1.
1.2 This standard is restricted to apparatus intended for the detection and measurement of
volume ratios of methane in air from a volume fraction of 0 % up to, but not exceeding. a
volume fraction of 5 %.
2 Definitions
For the purpose of this part of IEC 61779, the definitions given in part 1 apply.
3 General requirements
The apparatus shall comply with the general requirements specified in part 1 and with the performance requirements specified in clause 4 of this standard.
Compliance shall be determined in accordance with the appropriate test requirements and methods, including initial calibration, specified in part 1.
It shall be verified that the contents of the manufacturer’s instruction manual are in accordance with the requirements specified in part 1.
4 Performance requirements
4.1 General
The normal conditions for tests are specified in 4.3 of part 1. Compliance shall be determined in accordance with the test methods specified in 4.4 of part 1.
4.2 Unpowered storage
After being submitted to the conditions specified in 4.4.2 of part 1, the apparatus shall meet the requirements specified in 4.3 to clause 5 of this standard.
4.3 Calibration curve (not applicable to alarm-only apparatus)
After initial adjustment with the standard test gas, each individual indication in the three sets of indications (after correction using the manufacturer’s calibration curve, if necessary) obtained for each of the four gas volume ratios distributed over the measuring range shall not differ from these volume ratios by more than a volume fraction of ±0,1 % methane or ±5 % of the indication, whichever is the greater.
1.1 This part of IEC 61779 specifies requirements for group I (as defined in part 1) portable, transportable and fixed apparatus for the detection and measurement of methane concentrations in mine air. The apparatus, or parts thereof, are intended for use in mines susceptible to firedamp. The requirements and test methods applicable to the apparatus covered by this standard are specified in part 1.
NOTE — The use of group I apparatus may nol be permitted without the additional and prior approval of the relevant authority in mines under its jurisdiction, see note 1 of 1.1.1 of part 1.
1.2 This standard is restricted to apparatus intended for the detection and measurement of
volume ratios of methane in air from a volume fraction of 0 % up to, but not exceeding. a
volume fraction of 5 %.
2 Definitions
For the purpose of this part of IEC 61779, the definitions given in part 1 apply.
3 General requirements
The apparatus shall comply with the general requirements specified in part 1 and with the performance requirements specified in clause 4 of this standard.
Compliance shall be determined in accordance with the appropriate test requirements and methods, including initial calibration, specified in part 1.
It shall be verified that the contents of the manufacturer’s instruction manual are in accordance with the requirements specified in part 1.
4 Performance requirements
4.1 General
The normal conditions for tests are specified in 4.3 of part 1. Compliance shall be determined in accordance with the test methods specified in 4.4 of part 1.
4.2 Unpowered storage
After being submitted to the conditions specified in 4.4.2 of part 1, the apparatus shall meet the requirements specified in 4.3 to clause 5 of this standard.
4.3 Calibration curve (not applicable to alarm-only apparatus)
After initial adjustment with the standard test gas, each individual indication in the three sets of indications (after correction using the manufacturer’s calibration curve, if necessary) obtained for each of the four gas volume ratios distributed over the measuring range shall not differ from these volume ratios by more than a volume fraction of ±0,1 % methane or ±5 % of the indication, whichever is the greater.