Teledyne API Model 100AH SO2 Analyzer Instruction Manual, 02417, Rev. D
If the SPAN button is not illuminated when attempting to span, that means the reading is outside
of the software gain ranges allowed. In an analog instrument it would be the equivalent to the
span pot hitting the maximum.
Here are some things to check:
1. Check the expected span concentration value in CAL-CONC, and compare this to the value
of the calibrator span gas being input. They should be close.
2. Check ET (see Section 10.1.3.2) and OT (see Section 10.1.3.3) for a response on the PMT -
TEST function.
3. If the above do not check out, perform the Factory Calibration Procedure Section 10.1.6.
10.2.9 Inability to Zero If the ZERO button is not illuminated when attempting to zero, that means the reading is outside
of the software gain ranges allowed. In an analog instrument it would be the equivalent to the
zero pot hitting the maximum.
Here are some things to check:
1. Select the PMT - TEST function. With zero gas going into the instrument, the value should
be less than 50 mV, typically 10 - 30 mV. If you are getting a high reading, the probable
reasons are:
A. Leak that admits gas containing SO2.
B. Contaminated reaction cell. Remove and clean cell.
C. Light leak.
D. Zero gas that isn't really zero. Make sure you're not trying to zero the analyzer with
sample gas or span gas.
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