Honeywell Impact Series Operating Instructions And Maintenance Manual page 35

4.7.1.1 Flammable Cross-Sensitivity Table
Flammable Gas
Hydrogen
Methane
Ethylene
Methanol
Ethane
Ethanol
Propane
Butane
Pentane
Octane
Note
The above data are applicable only to instruments that have catalytic
sensors configured to display the Flammable gas in % LEL.
The previous table and the cross-sensitivity feature offered in the Impact and Impact
Pro are supplied for indicative purposes only. The following points should be noted
when using the table or the software feature.
1. There is variability in sensor cross-sensitivity between methane and other
flammable compounds. Therefore, if the instrument is calibrated to Methane
(including Enforcer calibrations), the reading when other Flammable gases
are selected will be subject to variation.
2. For more accurate detection of non-Methane gases, the Flammable Channel of
the instrument should be calibrated to Propane, Pentane or Butane (selectable
from the Settings option in the Calibration Menu). In this instance the reading
obtained when Methane is selected may be subject to inaccuracy.
3. Maximum accuracy will be obtained by calibrating with the target gas, and is
therefore the preferred method.
Target Gas Recommended Calibration Method
Enforcer
Methane UI Calibration (using Methane as the selected calibration gas)
PC Calibration (using Methane as the selected calibration gas)
UI Calibration (using Propane as the selected calibration gas)
Propane
PC Calibration (using Propane as the selected calibration gas)
UI Calibration (using Butane as the selected calibration gas)
Butane
PC Calibration (using Butane as the selected calibration gas)
UI Calibration (using Pentane as the selected calibration gas)
Pentane
PC Calibration (using Pentane as the selected calibration gas)
Other
UI Calibration (using Propane, Butane or Pentane as the selected calibration gas)
flammable
gases PC Calibration (using Propane or Butane as the selected calibration gas)
Impact / Impact Pro / Impact Pro IR Operating Instructions
EN50054
Relative Sensitivity
(% of Methane Reading)
125
100
91
83
90
67
68
56
56
42
EN61779
Relative Sensitivity
(% of Methane Reading)
142
100
88
95
85
71
66
59
63
47
35