Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2 9-3 The Table 9-1 indicates possible fault conditions that could cause the TEST functions to be outside the acceptable range. Table 9-1: Test Functions
Test Function Factory Set-Up Comment
RANGE 500 PPM This is the Range of the instrument. In single range mode (standard
configuration) all 3 outputs have the same range. If NOx range-2 is
enabled there will be an indication of the range for this output.
Auto range option allows 2 different ranges for instrument output,
and will automatically switch all outputs to the other range
dynamically as concentration values require. The TEST values will
show the range the instrument is currently operating in, and will
dynamically display the alternate range as the range changes occur.
Independent range option allows different ranges for each output.
When enabled, there will be 3 range values displayed. If NOx
range-2 is enabled there will be an indication of the range for this
output making a total of 4 range indications.
STABIL Check value in
Final Test Values
Table 2-1
The instrument noise is determined by computing the standard
deviation of the last 10 minutes of data. It is computed using NOx
channel data when in the NO/NOx switching mode or NOx only
mode. When in the NO only mode it uses the NO data. The noise
value only becomes meaningful if sampling a constant
concentration for more than 10 minutes. The noise value should be
compared to the value observed in the factory check-out.
Faults that cause high noise values are:
1. Gas leaks
2. Light leak
3. Faulty HVPS
4. Defective Preamp board
5. Outgassing Moly converter
6. PMT recently exposed to room light
7. Dirty/contaminated reaction cell
8. Mis-calibrated (slope - offset outside of limits)
(table continued)