RKI Instruments Gas Tracer - Manual (Page 42)

34 • Measuring Mode, Normal Operation Gas Tracer Operator’s Manual
you are detecting pentane and the display reads 10% LEL on the combustible
gas channel, you actually have 10% LEL x 1.35 = 13.5% LEL pentane
present.
CO with H
2
S Response Configuration
Some applications may require the user to know if H
2
S is present
while monitoring with a Gas Tracer. The Gas Tracer does not have an
H
2
S sensor installed but if the charcoal filter is removed from the CO
sensor, it will respond to H
2
S.
Since the CO sensor cannot distinguish between CO and H
2
S, the CO
channel reading on the display could be a mix of CO and H
2
S.
If the environment you are monitoring is completely free of CO, there
is an approximate response factor that varies from sensor to sensor
that can be used. The CO sensor’s response to H
2
S is 5 times greater
than the actual H
2
S concentration. For example, if the CO channel
reading is 25 ppm, the actual H
2
S concentration is 5 ppm. This
approximation is not applicable if CO is present in the monitoring
environment.
NOTE: If your Gas Tracer is configured to respond to both H
2
S and
CO, be sure to calibrate the CO channel using CO.
Table 3: LEL Hydrocarbon Conversions
Gas
LEL Conversion
Factor (Methane
Calibration)
Gas
LEL Conversion
Factor (Methane
Calibration)
Acetone 1.92 Iso Butane 1.56
Acetylene 2.00 MEK 1.92
Benzene 2.00 Methane 1.00
Ethane 1.25 Methanol 1.65
Ethanol 1.75 Pentane 1.35
Ethylene 1.20 Propane 1.52
Heptane 1.92 Propylene 1.33
Hexane 1.65 Toluene 2.00
Hydrogen 1.00 Xylene 0.93
IPA 2.50