121
Faulty membrane
Replace membrane cap.
High Pressure
Reduce pressure to below 1 atmosphere and refill cap with electrolyte
No electrolyte fill solution in membrane cap
Fill membrane cap with electrolyte. Replace membrane cap if it will not
hold solution.
Improper wiring of sensor to controller
Correct wiring
Faulty sensor
Replace sensor
Faulty analysis equipment or reagents
Consult test equipment instructions
Sample contaminated with interfering molecule refer
to Sensitivity specification in sensor instructions)
Remove source of contamination
8.1.6 Analog Inputs
The calibration will fail if the adjustment to the gain is outside of 0.5 to 2.0, or if the calculated offset is outside
of -2 to 2 mA.
Possible Cause
Corrective Action
Improper wiring of sensor to controller
Correct wiring
Faulty sensor
Replace sensor
8.1.7 Temperature Sensors
The calibration will fail if the calculated offset is outside of -10 to 10.
Possible Cause
Corrective Action
Improper wiring of sensor to controller
Correct wiring
Temperature input is set to the incorrect element
Reprogram to match the connected temperature element
Faulty sensor
Replace sensor
8.1.8 Corrosion Inputs
The calibration will fail if the corrosion rate or imbalance value entered is outside the range of 0 to 5 times the
corrosion rate Range setting.
Possible Cause
Corrective Action
Improper wiring of sensor to controller
Correct wiring
Range settings is too low
Increase the Range setting
Electrode tips have not conditioned long enough
Allow time for electrodes to condition
Old electrodes
Replace electrodes and consider setting an Electrode Alarm
reminder
Electrodes not tight
Tighten electrodes
Electrodes are not completely submerged
Install sensor in the side branch of a tee, not the top
8.2 Alarm Messages
HIGH or HIGH-HIGH ALARM
Occurs if the sensor reading rises above the high alarm set points. If your unit is programmed for an alarm relay output, the alarm
relay will activate. The controller will continue to check the sensor reading, and any outputs using the sensor will remain active.
Possible Cause
Corrective Action
The process went further out of control than normal.
May have to increase chemical flow rate.
The chemical supply has run out.
Replenish the chemical supply.
The pump or valve or supply line is faulty.
Repair or replace the control device.
Wrong chemical is being controlled.
Replace with correct chemical.
The sensor is not responding to changes.
Repair or replace sensor. Evaluate mixing or recirculation.
The pump is siphoning, valve leaking.
Repair or replace the control device or re-route tubing.
