Model 202 Ozone Monitor Manual Rev. J-4
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7. PERIODIC ZERO AND SPAN CHECKS
To ensure the quality of the ozone monitor data, periodic zero and span checks can
be performed by following the steps below:
1. A zero check is performed by sampling zero air with the Model 202
following the “Measurement of Zero Air” Section 6.6.2 above.
2. A span check is performed by sampling an ozone concentration at the high
end of the concentration range of interest following the
“Measurement of
Ozone Standards” Section 6.6.3 above.
3. Average measurements from the zero check or span check should be within
the instrument specifications. If the measurements are not within
specifications, this is an indication of problem in the calibration setup or the
ozone monitor being checked. The most likely problems in the ozone
monitor are leaks, a malfunctioning ozone scrubber, a contaminated valve,
or contamination in the optical setup. See the “Troubleshooting” section of
the manual (Section 8).
