Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
7-11
7.6. NO Only Mode Calibration
For details on the operation of this mode, check Section 5.4. In NO only mode, the span check or
span calibration is operated using the same procedures covered in Sections 7.1 to 7.5. The main
difference to note is that only one channel, namely the NO channel will be checked or calibrated.
For example in Table 7-3 - Entering the Expected Span value, only the NO concentration is
required. The NO/NOx valve is continuously in the NO mode. And since the converter is never
switched into the sample gas stream, none of the converter efficiency procedures apply.
7.7. NOX Only Mode Calibration
For details on the operation of this mode, check Section 5.4. In NOX only mode, the span check
or span calibration is operated using the same procedures covered in Sections 7.1 to 7.5. The
main difference to note is that only one channel, namely the NOX channel, will be checked or
calibrated. For example in Table 7-3 - Entering the Expected Span value, only the NOX
concentration is required. The NO/NOX valve is continuously in the NOX mode.
Since the instrument is always in NOX mode it is not possible to apply converter efficiency
compensation to the NOX value. This is because the efficiency should only be applied to the NO2
portion of the signal. The valve never switches to measure the proportion of NO in the sample
gas, therefore the fraction of the sample that is NO2 is unknown.
It is recommended that the converter efficiency be measured when the instrument is calibrated.
This procedure is covered in Section 7.10.
7.8. Calibration Requirements for AutoRange or Remote
RangeIn AutoRange there are two separate calibrations for Low range and High range. There are 2
independent slopes and 2 offsets and 2 sets of converter efficiency parameters. The instrument
applies the appropriate values depending on whether the instrument is in low range or high
range.