Rae QRAE PLUS PGM-2000, Руководство по эксплуатации и техническому обслуживанию

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APPENDIX B
B - 1
LEL Correction Factors
Correction factors (CFs) for a number of commonly used
compounds for the LEL sensor are on the facing page. The
factors are measured relative to methane. After calibration to
methane, multiply the reading by the factor to obtain the actual
% LEL of the gas. If the CF of a gas is <1.0, then the sensitivity
to the gas is higher than that of methane. The factors are
typically measured at 50% LEL, less than 5% relative humidity
and 77°F (25°C). The CFs may change at other
concentrations, but temperature and humidity variations usually
have little effect on the sensor response. The CFs are for new
sensors and may change with age.
CAUTION!
The LEL CFs listed in Table 14 should not be confused
with CFs for volume % measurements using the thermal
conductivity (TC) function of the sensor. See Technical
Note 153 at
www.raesystems.com for CFs for Vol%
measurements. The CF’s are subject to change; check
Technical Note 156 for the latest LEL CF updates.
LEL CFs may change as the sensor ages. Typically the CFs
decrease, therefore use of the values above will err on
the safe side.