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5–22
5.0 Maintenance & Troubleshooting
Teledyne Analytical Instruments
A Business Unit of Teledyne Electronic Technologies
r. Check pins 8 and 10 on amplifier A3 for presence of +5
volt square wave on scope.
s. Switch NORM/REF to REF. Adjust R36 to give 90% of
scale (9 VDC) on the analysis section meter.
t. Switch to MEAS. Meter should read 9 volts.
u. Switch the NORM/ZERO switch to ZERO position.
Adjust the coarse ZERO to cause the meter to read zero.
The ZERO control should end up around 500.
v. The remainder of the adjustments on this PCB must be
made by TAI Photometric personnel
E-to-I Converter for Analysis Unit
Refer to dwg. B-14075. This unit will have 10 to 20 mA output, with 0
to 0.5 volts input. This means when operating at the recommended range of
0 to 0.4 volts from the log PCB, the output from E-to-I PCB will be 10 to 18
mA.
1. Insert this board in the analyzer using a card extender.
2. Adjust the coarse ZERO control, on the power module, for zero
volts into the E-to-I converter. Measure this voltage with a DMM
at TP1 (red) on the log board or at pin 6 of the E-to-I circuit
board connector.
3. Adjust R7 to give 10 mA output between pins 1 and 13.
4. Adjust the coarse ZERO control to give 0.5 volts in at pin 6.
In some cases you may not be able to adjust from 0 to 0.5 volts.
Since the E-to-I board gives a linear current output with voltage,
the following formula can be used to calculate the current output
(I out) in mA relative to voltage in (V in)
I out = 20 (V in) + 10mA
5. Adjust R12 to obtain 20 mA or the appropriate output determined
in step 4 between pins 1 and 13.
6. Repeat steps 2 through 5 until the results are reproducible.
Note:
This card is the last PCB located in the detector condulet.