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Troubleshooting – GF Signet 8850 ProcessPro Conductivity-Resistivity Transmitter User Manual

Page 10

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10

8850-3 Conductivity/Resistivity Transmitter

Display Condition

Suggested Solutions

Possible Causes

"- - - -"

Value Must be less
than 3

Value must be greater than 0

"Value must be
400 or less"

Display erratic, shows "0" or
"------"

intermittently

"Too much Error
Check Sensor"

Display is over range. This may be a
normal condition if your process operates
at/near the limits of the sensor range.
kΩ or MΩ units selected and sensor is
open.

The PPM factor must be a value from
0.00 to 3.00.

Custom cell constant cannot be set to 0.

Pulse Rate cannot be greater than 400.

Aux Power not connected.

• Defective or dirty/coated sensor.
• Wiring error.
• Fluid conductivity too low.
• Defective temp element.

• Check sensor for correct range.
• Check Decimal setting in OPTIONS menu.
Check Calibrate menu settings for incompatible

SOURCE and RANGE values.

Set a PPM value less than 3.

Set cell constant to a value greater than 0.

Set a pulse rate value less than 400.

Wire 8850 according to diagram (Section 3.1).

• Clean or replace sensor.
• Check and correct wiring.

• Replace sensor.

Troubleshooting

If a Current Loop is locked at 3.6 mA, the problem is related to the temperature circuit:
This occurs only if the 8850 detects a resistance from the temperature sensor that is less than 250

or greater than 2800 .

• Check the sensor wiring for open/short or poor connections on white (TEMP IN) and black (ISO GND)wires.
• The PT1000 temperature device in the sensor is defective.
• The transmitter is defective.

Auxiliary Power (terminals 1 and 2) must ALWAYS be connected for the 8850 to operate.

Technical notes