Walchem W600 Series Instruction Manual page 91

NO SAMPLE
No Sample will be displayed if the measurement signals indicate excess air in the sample. In the Input Details menu, both the Sample
Measurement and Sample Reference mV will be between 0.4 and 0.7 times what the readings were in water during the last Water/
Sample Calibration (Water Measurement and Water Reference mV).
Liquid level too low for immersible sensor
Sample pump failure
Leak in or blockage of the sample line
Excess air in sample tubing
Contamination of the bath
Faulty sensor
Controller is faulty
LAMP OUT
Lamp Out will be displayed if the measurement signals indicate almost no light getting through. In the Input Details menu, both the
Sample Measurement and Sample Reference mV will be less than 0.01 times what the readings were in water during the last Water/
Sample Calibration (Water Measurement and Water Reference mV).
Possible Cause
Sensor wire(s) disconnected
Lamp failure
Dirty sensor
Faulty sensor
Controller is faulty
PLATE OUT
Plate Out will be displayed if the measurement signals indicate very light getting through. In the Input Details menu, both the Sample
Measurement and Sample Reference mV will be less than 0.4 times what the readings were in water during the last Water/Sample
Calibration (Water Measurement and Water Reference mV).
Water/Sample Calibration has not been performed, or performed
incorrectly
Dirty sensor
Faulty sensor receptacle on controller
Faulty sensor
Controller is faulty
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
The process went further out of control than normal.
The chemical supply has run out.
The pump or valve or supply line is faulty.
Wrong chemical is being controlled.
The sensor is not responding to changes.
The pump is siphoning, valve leaking.
Control output has been left in "HAND" mode.
It may be a normal part of the process.
LOW or LOW-LOW ALARM
Occurs if the sensor reading drops below the low 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
The process went further out of control than normal.
Raise level or lower sensor
Repair or replace sample pump
Repair sample line
Purge sample line of air. Check for leaks. Check orientation of
sensor. Make sure sample line inlet is not placed where there is air
or gas in the tank.
A chemical in the bath may be absorbing at the reference wave-
length. Test the sensor in a sample of uncontaminated copper
solution.
Repair or replace sensor
Repair or replace controller
Corrective Action
Reconnect.
Replace lamp
Clean or etch sensor
Repair or replace sensor.
Repair or replace controller
Perform a Water/Sample Calibration
Clean or etch sensor
Replace
Repair or replace sensor
Repair or replace controller
Corrective Action
May have to increase chemical flow rate.
Replenish the chemical supply.
Repair or replace the control device.
Replace with correct chemical.
Repair or replace sensor. Evaluate mixing or recirculation.
Repair or replace the control device or re-route tubing.
Switch back to "AUTO".
None required.
Corrective Action
May have to increase chemical flow rate.
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