Walchem WebMaster ONE Instruction Manual page 68

Calculated Offset
This displays the mV output of the pH electrode in pH 7 as of the last calibration. A perfect
electrode will generate 0 mV at pH 7. The offset information is also helpful for troubleshooting.
% Difference from theoretical
This displays the % difference of the slope from the theoretical value as of the last calibration. The
higher this percentage, the weaker the pH electrode. The calibration will fail if this percentage
exceeds 80%. This number is the most useful to determine how much life is left in the electrode.
High-High Alarm Limit
Type in the text box the sensor process value above which you a want a high-high alarm to occur.
High Alarm Limit
Type in the text box the sensor process value above which you a want a high alarm to occur.
Low Alarm Limit
Type in the text box the sensor process value below which you want a low alarm to occur.
Low-Low Alarm Limit
Type in the text box the sensor process value below which you want a low-low alarm to occur.
Alarm Dead Band
Type in the text box the dead band to be used for each alarm set point.
Damping
Damping is applied to the sensor input by taking a running average of the readings of the input
signal over the time frame specified by the damping setting (0-60 seconds)
is displayed and used for control. Type in the text box the desired time frame.
Temperature
Note: The temperature sensor detection is checked when the WebMasterONE is powered up.
Make sure that the sensor connections are made prior to turning on the power.
Current Temperature
Displays a live reading of the temperature of the system water. If no temperature sensor is
detected at power-up, this will be "Manual Temperature" and allow the temperature to be typed
into the text box.
Status
Possible status messages are; Normal (everything is OK), Sensor Error (the signal is not valid),
High Alarm, or Low Alarm. See section 8.1 for a complete description of error messages.
Calibrate
Click on the "Calibrate" button and a new window will open that read "To Modify the Current
Value", and displays the current reading and a text box in which to type the actual value. Measure
the temperature of the sample with a thermometer, and type the actual value into the text box.
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The averaged reading
.