RKI Instruments GX-2009 Manual - Manual (Page 25)

GX-2009 Operator’s Manual Operation • 20
7. Press and release the POWER MODE button again to return to
Measuring Mode.
NOTE: If you do not press a button for 20 seconds while in Display Mode,
the GX-2009 will return to Measuring Mode automatically and the
backlight will turn off 30 seconds since the last button was
pressed.
Combustible Gas Detection
There are three issues that must be considered when monitoring for
combustible gas.
• The combustible sensor will respond to any combustible gas. The
standard calibration gas for the GX-2009 combustible channel is
methane (CH4). If the instrument is calibrated to a different combustible
gas, such as hexane or propane, the gas name for the combustible
channel may be set to HC by using the GX-2009 Setup Program. See
the GX-2009 Setup Program Operator’s Manual for information on how
to set the combustible gas name.
The table below lists the conversion factors for several hydrocarbon
gasses if the GX-2009 is calibrated to methane. To use this table,
multiply the display reading on the combustible gas channel by the
factor in the appropriate row to obtain the actual gas concentration. For
example, if you are detecting pentane and the display reads 10% LEL
on the combustible channel, you actually have 10% LEL x 1.56 = 15.6%
LEL pentane present.
Table 3: LEL Hydrocarbon Conversions
Gas
LEL Conversion
Factor (CH
4
Cal.)
Gas
LEL Conversion Factor
(CH
4
Cal.)
Acetone 1.79 Iso Butane 1.47
Acetylene 1.92 MEK 2.27
Benzene 2.00 Methane 1.00
Ethane 1.09 Methanol 1.92
Ethanol 2.50 Pentane 1.56
Ethylene 1.06 Propane 1.35
Heptane 2.50 Propylene 1.32
Hexane 2.08 Toluene 3.13