Ph/Redox/Orp - ABB AWT420 Operating Instruction

AW T4 2 0 | U N I V E R S A L 4 - W I R E , D U A L- I N P U T T R A N S M I T T E R | O I/A W T4 2 0 - E N R E V. B

pH/Redox/ORP

Menu Comment
Tag
Enter an alphanumeric sensor tag (16 characters maximum) to identify the sensor on the
Operator Pages .
Measurement Type Select measurement type:
• pH/Redox/ORP
Note. If a change is made the I/O sources are reset.
Range High
Set the span value used in Chart and Bargraph views.
Range Low Set the zero value used in Chart and Bargraph views.
Filter Type
Select the signal filtering type:
• None/Low/Medium/High
Note . The following menus are displayed only if Measurement Type = pH.
Temp . Compensation
Set the type of temperature compensation:
• Manual/Automatic/Auto solution
Solution Coeff . Note. Displayed only if Temp. Compensation type = Auto solution.
Set the solution coefficient (pH or mV change per 10 deg C) of the solution being monitored.
See Appendix A, page 97.
Manual Temperature Note . Displayed only if Temp. Compensation type = Manual.
Enter the temperature of the sample within the range –10.0 to 120.0 °C.
Note . The following menus are displayed only if Measurement Type = Redox/ORP.
Temperature Sensor
Set the type of temperature measurement:
• Manual/Automatic
Note . If Temperature Sensor type = Manual, the temperature value is not displayed in the associated
Operator page or Signals View.
Low Slope Limit A pH probe degrades over time. As this happens the slope calculated by a calibration procedure gradually
decreases. Set the slope value below which a calibration fails. The low slope warning diagnostic is
activated if the calibration calculates a slope less than 20 % above this value.
Sensor Diagnostics
Broken Glass Note: Displayed only if Measurement Type = pH.
Detect broken glass condition:
• Enabled/Disabled
Out Of Solution
Detect Out Of Solution condition:
• Enabled/Disabled
Ref . Poisoning Note: Displayed only if a digital (EZLink) sensor is connected.
Detect a contaminated reference electrode:
• Enabled/Disabled
Ref . Failure Note: Displayed only if a digital (EZLink) sensor is connected.
Detect a failed reference electrode:
• Enabled/Disabled
Ref . Blocked
Detect a blocked reference electrode:
• Enabled/Disabled
Ref . Alarm Limit Note: Displayed only if Ref. Blocked sensor diagnostic is Enabled.
A blocked reference electrode is detected when the impedance of the reference electrode exceeds
a given limit. Set the impedance value above which the reference blocked diagnostic is activated.
Reset To Defaults
Select to reset all Sensor Setup parameters to their default values.
53
Default
TAG1
pH
14.00
0.00
None
Automatic
N/A
N/A
N/A
40%
Disabled
Disabled
Disabled
Disabled
Disabled
N/A