Teledyne 6750 - Total Organic Carbon analyzers - Manual (Page 80)

Maintenance Model 6750
Teledyne Analytical Instruments 68
5.3.13.1 S ETTING 100 M V C ONTROL V OLTAGE
1. Using a DC voltmeter, connected to measure DC voltage,
connect the black lead to the (-) side of capacitor C1.
Located near the lower left corner of the circuit board.
Connect the (+) lead to the top of resistor R19, located
slightly to the left of the center of the circuit board. Note
the mV reading (typically no greater than 3 mV).
2. Next, position the Analog A cursor to Max position.
Note the mV reading from the top of R19. Use pot R21
located slightly to the right of the center of the circuit
board to adjust the mV reading 100 mV higher than
minimum reading. Reposition Analog A to Min and re-
check Min and Max mV readings.
5.3.13.2 S ETTING OF 4-20 M A OUTPUT
1. Using a digital voltmeter connected to read mA, connect
the black lead to #1 4-20mA out (-) and the red lead to #1
4-20 mA out (+).
2. Adjust R41 for 4mA when Analog A is at minimum.
Adjust R42 for 20mA when Analog A is at Maximum.
Repeat Analog Min/Max until 4-20 mA is achieved.