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Thermo Fisher Scientific
The analyzer does a one point NO
corrects the NO
reading for converter inefficiency, and then adds the
2
corrected NO
to the NO signal to give a corrected NO
2
If the analyzer calculates a NO
the entered NO
concentration is incorrect, the converter is not being
2
heated to the proper temperature, the instrument needs servicing (leak
or imbalance), or the converter needs replacement or servicing. The
NO
analog output will reflect the NO
2
GPT, any NO
impurity, and the NO
2
The recorder response will be as follows:
Recorder R
esponse
Where:
URL = Nominal upper range limit of the NO
12. Record the NO
concentration and the analyzer's NO
2
13. Maintaining the same F
obtain several other concentrations of NO
five evenly spaced points across the remaining scale are suggested).
14. Record the stable responses and plot the analyzer's NO
versus the corresponding calculated (using the above equation for
[NO
]
) concentrations and draw or calculate the NO
2
OUT
curve.
Note It is important that the curve be linear within ±1 % FS over the NO
range. If the curve is nonlinear, the analyzer is not operating correctly,
(possible leak, or converter failure, etc.), and should be serviced. Assuming
the curve is linear, subsequent data should be reduced using this NO
calibration curve response.
Using the Calibration Factors menu can change the calibration factors.
This is often useful in a troubleshooting situation. However, after the above
calibration procedure is completed, all subsequent data reduction depends
on the calibration parameters, remaining the same as during the initial
calibration.
▲
span coefficient calculation,
2
span coefficient of less than 0.96, either
2
concentration generated by
2
zero offset.
2
[
]
NO
2
OUT
(%
scale)
=
URL
channel, ppm
2
, F
, and F
, adjust the ozone generator to
NO
O
D
over the NO
2
▲
Model 42i Trace Level Instruction Manual
Calibration
Calibration
signal.
x
x
100
+
Z
NO
2
response.
2
range (at least
2
responses
2
calibration
2
2
4-15
2
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Troubleshooting
