Section 11
Model 601/601P/602/602P/603 NDIR Analyzer
California Analytical Model 600_NDIR_Series_v10.0 CE
Operators Manual
Page 72 of 86
11.9. Check and Repair Amplifier Circuit
1)
Connect an oscilloscope across check terminals TP3 (signal) and TP9 (common)
and observe the ac waveform. While zero gas is flowing, the amplitude of the
waveform should be between 2.48Vpp and 2.8Vpp as shown below. This can be
adjusted by following the procedure described under section 12.2 before making
this adjustment it is recommended that a check for contamination in the cell and
cell windows be done first, as this can lead to a reduction in amplitude of the ac
signal.
Note: Check cell first for contamination and clean if necessary.
2.48/2.8V peak-to-peak
10Hz
Figure 11-1 Amplifier circuit ac wave form
2)
If an ac waveform cannot be observed in step a) above, observe the ac
waveform across terminals TP4 (signal) and TP9 (common). If an ac waveform
of 10 Hz and “peak-to-peak” amplitude of 147mV to 164mV is observed, ac
amplifier U1 is normal and AC amplifier U7 is not functioning.
3)
If an AC Waveform is not observed across terminals TP4 (signal) and TP9
(common), check the detector per section 12.4 of this manual.
Summary of Contents for 600-NDIR
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