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3.7 Calibrating the 4 to 20mA Output
The 4 to 20mA output of the
mini
CHEM
-Cond
is factory calibrated. However,
TPS has provided calibration controls for the 4mA and 20mA points in case this
requires adjustment in the field. Only a limited amount of adjustment is available,
as the
mini
CHEM
-Cond
is designed for 4 to 20mA output for the full scale of the
instrument.
Calibrating the 4 to 20mA output…
1. Connect a Digital Milliamp Meter between terminals 7 and 8.
2. Switch the
mini
CHEM
-Cond
to
SET LIMIT
.
3. Adjust the
LIMIT
control until the display reads 0.00.
4. Adjust the
ZERO/4mA
trimmer in the terminal area until the Digital
Milliamp Meter reads 4 mA.
5. Adjust the
LIMIT
control until the display reads 1999, regardless of decimal
point location.
6. Adjust the
SPAN/20mA
trimmer in the terminal area until the Digital
Milliamp Meter reads 20 mA.
In the event that the
LIMIT
control does not have sufficient adjustment to
reach 0.00 or 1999, calculate the expected output level and use this for
calibration. Remember that the difference between 0 and 1999 is to be made
16mA.
