5.6 Combustible Gas Cross Reference Factors
General purpose calibration using Calibration Cylinder P/N 10045035
set to 58% LEL Pentane Simulant.
Gas
Butane
Hydrogen
Methane (ATEX, 4.4% VOL)
Methane (UL, CSA 5.0% VOL)
Propane (ATEX, 1.7% VOL)
Propane (UL, CSA 2.1% VOL)
Pentane
Notes:
1. For an instrument calibrated on Pentane, multiply the displayed %LEL value by the
conversion factor above to get the true %LEL.
2. These conversion factors should be used only if the combustible gas is known.
3. These conversion factors are typical. Individual units may vary by +25% from these
values.
4. The results are intended for guidance only. For the most accurate measurements,
an instrument should be calibrated using the gas under investigation.
Multiply LEL readings by:
1.0
0.5
0.6
0.5
1.0
0.8
1.0
5-7