Teledyne 514 - NDIR analyzer - Manual (Page 62)

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5.0 Maintenance & Troubleshooting
Teledyne Analytical Instruments
A Business Unit of Teledyne Electronic Technologies
Extended Voltage Amplifier
See dwg. B-16221. To adjust the offset voltage of Q1:
1. Remove the I-to-E converter.
2. With zero volts into pin 2 install a meter at the output of Q1.
3. Adjust R1 for zero offset at the output of Q1.
4. Reinstall the I-to-E board.
Meter Trim & Output Voltage Calibration
For localized explosion-proof control modules, the trim calibration is
done as in the “Meter Trim Circuit Adjustment” section under Log Amplifier
PCBs.
For the General Purpose Control Unit Models:
1. Place a DMM on the output pin 6, on Q1 or circuit board
connector pins. Set the SPAN setting to 250 or higher.
2. Adjust the coarse ZERO potentiometer on the power module to
give zero volts on the DMM. The control unit meter should read
zero.
3. Adjust the coarse ZERO potentiometer to give the full scale
output voltage on the DMM (generally 1.00 volt). If the 0-1 volt
adjustment cannot be made with the coarse ZERO, increase the
span control setting.
4. Once the instrument is set for the proper output voltage, adjust
R5 to make the control unit meter read exactly 100% of full scale.
Check a few points in between 0 and 100% to see if the output
tracks with meter reading in a linear fashion.
Control Unit Options
E-to-I Converter
See dwg. B-16631.
1. Install R1 per current output desire (see “Control Unit E-to-I”
under Component Selection). With zero volts in adjust R7 until
the desired lower current output level is obtained.