ABB AWT420 User Manual

AWT420 | UNIVERSAL 4-WIRE, DUAL-INPUT TRANSMITTER | OI/AWT420-EN REV. B
79
In Process calibration
In process calibration is used when it is not possible to remove
the sensor from the process to perform the calibration. In this
calibration mode the actual sample is used to calibrate the
sensor.
The in process calibration takes place in two steps:
• Sample collection
 A grab sample is taken from the process and the sensor
records the measured value of the sample at that time.
Note. The grab sample should be taken as close to the
sensor as possible during the data collection period.
• Collection complete
 The Total suspended solids of the sample is measured in the
laboratory and entered into the transmitter.
This sample must correspond to the last sample collection
step performed.
Sample collection
1 At the Calibrate level, press the key:
The Calibrate menu is displayed:
2 Use the / keys to select the sensor to be calibrated,
and press the key to confirm selection.
The Sample Collection menu is displayed:
3 Use the / keys to select Sample Collection and
press the key to proceed to the next step.
4 Press the and key to proceed to the next step.
The collection process screen is displayed:
On completion the collection complete screen is displayed:
The value of the sample turbidity is now stored.
Note. The calibration can be canceled at any time during
the process by pressing the Abort key ( ).
Calibrate
Back
Select
S1 : Turb TSS
S2 : Turb TSS
Hold Outputs
Calibrate
Back
Select
Sensor Cal
Temperature Cal
Edit Cal
Sample Collection
Collection Complete
Restore Cal Defaults
Collect Sample
Start Collection
Abort
Continue
Calibrate
PV 3985 mg/l
NTU 4000 NTU
Settling - Please Wait
Abort
Calibrate
PV 3985 mg/l
NTU 4000 NTU
Procedure Complete
Abort

ABB AWT420 Specifications

General

Brand	ABB
Model	AWT420
Category	Transmitter
Language	English