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Teledyne 514 - NDIR analyzer User Manual

Page 55

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5–17

Maintenance & Troubleshooting 5.0

Teledyne Analytical Instruments

A Business Unit of Teledyne Electronic Technologies

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: