Thermo Scientific TVA2020 Instruction Manual page 189

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expressed as "100 ppm of Methane" if the calibration gas used was
Methane. Please note that the TVA2020 detectors can be calibrated
with gases other than the factory standards as long as the detector has
adequate response to that compound.
2. Response factor corrected
If the TVA is used to measure a single known compound, a response factor
from this set of response curves can be applied to correct the TVA reading
for that compound. For example, if a survey of Acetone vapors yields a PID
reading of 100 ppm, the response factor multiplier from the Acetone curve
(1.417) could be applied to the reading to obtain the result of 141.7 ppm
Acetone.
3. Relative to a standard other than the calibration gas
If a regulatory agency requires that data be referenced to a standard other
than the calibration gas, the response factor for that standard can be applied
to the reading. For example, suppose that a survey of total volatile organics
must be measured, but the results must be reported in equivalents of
benzene. The FID calibrated with methane can be used and the benzene
response factor applied to correct the reading.
Response Factors
Response Factors
TVA2020 Instruction Manual C-3