4-Electrode Conductivity - 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

4-electrode conductivity

Menu
Calibrate
Exit Select
Menu Comment
Conductivity Cal See typical procedure, see page 58.
Concentration Cal
See typical procedure, see page 58.
Resistivity Cal
See typical procedure, see page 58.
Temperature Cal See Temperature Calibration procedure, see page 69.
Edit Cal
PV Slope Edit the PV Slope value.
Valid slope values range from 80 to 120 %
PV Offset Edit the sensor PV Offset.
Valid offset values are:
• ±20 µS/cm for cell constants of 1.00
• ±4 µS/cm for cell constants of 0.10
• ±0.8 µS/cm for cell constants of 0.01
Edit the Temperature Slope value.
Temperature Slope
Valid slope values range from 40 to 160 %
Temperature Offset Edit the Temperature Offset value.
• Valid offset values are ±40 °C.
Restore Cal Defaults Resets slope and offset values to factory default.
The conductivity/concentration/temperature calibration is a smart one-point calibration
routine that allows for single- or dual-point calibrations. By initiating calibrations at two
different conductivity/concentration/temperature values having ample separation, the
AWT420 transmitter automatically adjusts the offset, slope, or both to obtain the best sensor
performance.
Because this routine uses only the most recent calibration data, calibration can be conducted
throughout the sensor's life thus ensuring consistent sensor performance. If an incorrect
calibration is entered, the Restore Cal Defaults option returns the transmitter calibration values
to factory settings.
The AWT420 transmitter can be configured as a conductivity or concentration device, the smart
one-point calibration routine automatically uses the same units as the measured process
variable.
Note. Access to the Calibrate menu is via Calibrate and Advanced levels only.
57
Default
N/A
N/A
N/A
N/A
100 %
0 µS/cm
100 %
0 °C
N/A