PerkinElmer Photovac MicroFID, User Manual

Page: 83 / 170

Detailed Operation
with the recommended span gas and entering the appropriate
response factor. The response factor is based on the ratio of the
response of the specific compound to the response of the span gas.
The response factor multiplies MicroFID’s reading then displays
and records it (if the datalogger is on).
Response Factors on page 149 provides a list of response factors
from which approximations can be made for guidance purposes.
Data extrapolated from the use of response factors must be regarded
as interim and approximate only. The response factors in the list
should be used only for concentrations up to 500 ppm of the
specific compound, as response factors change with concentration.
To use the response factors:
1. Press the CAL key and enter the response factor for the
specific compound.
2. Calibrate MicroFID with zero air and 500 ppm methane as
described in Calibration on page 65.
3. Expose MicroFID to the sample. The displayed reading is
the approximate concentration of the specific compound.
The response factors on page 149 serve as a guide to concentrations
measured by MicroFID.
Results are expected to be accurate to /­10 ppm or +/­25%
of result, whichever is greater. Accuracy of response factors to other
gases and vapors may differ from that stated.
NOTE:
It does not matter which Cal Memory is selected or which response
factor is entered, MicroFID’ s response is not specific to any one
compound. The displayed reading represents the total
concentration of all ionizable compounds in the sample.
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