Teledyne 514 Instruction Manual page 55

4. Using a digital multimeter (DMM) at TP4 (orange) adjust P2 on
the AGC PCB until 9 volts is obtained.
5. With the meter at TP3 (yellow) adjust R3 of the peak level
detector until 9 volts is obtained.
6. Repeat steps 3 and 4 until both TP4 and TP3 read +9.0 VDC.
This represents the zero absorbance condition.
Log Amplifier PCBs
One of three different types of log boards is selected, depending on the
application. Insert the appropriate log PCB in the analyzer, using a card
extender. The meter trim circuit adjustment (below) is common to all three
log boards. The three sections after that describe individual log amplifier
adjustments.
Meter Trim Circuit Adjustment
This adjustment calibrates the local meter so that its readings correlate
with known voltages in from the peak level detector (PLD).
General Purpose Control Unit:
1. Set the power module control functions as follows: MEAS/REF
to REF, NORM/ZERO to NORM.
2. Adjust the meter trimpot until the meter reads 90% of full scale.
The meter trimpot on the chopper stabilized log amp (C-14586)
and the log ratio board (C-14907) is R36, and on the adjustable
log ratio board (C-14907) is R26.
3. Now turn the MEAS/REF switch to the MEAS position. The
local meter should read 9 VDC if the PLD adjustments were
properly done.
Explosion Proof Control Unit:
Teledyne Analytical Instruments
A Business Unit of Teledyne Electronic Technologies
Maintenance & Troubleshooting 5.0
5–17