Diagnostics
Document No. D113-015
Page 66 of 77
Revision 1.9
Figure 5.21 – Channel Status – Input Calibration
The module is Factory Calibrated, and should not require any further calibration before use.
To re-calibrate the module, the User Calibration methods described below can be
implemented.
5.5.1.
I
NPUT
C
ALIBRATION
:
To re-calibrate a HART 4 Input module,
1.
Using an external milliamp source, adjust the current to 4mA, or as close as possible to 4mA.
2.
Enter the exact milliamp value, read from an external meter, into the
Low Value
Actual
numeric inputs.
3.
Press the
Low Value
(4mA)
Capture
button, to capture the current (un-calibrated value) into the
Raw
Capture
field.
4.
Using the external milliamp source, adjust the current to 20mA, or as close as possible to 20mA.
5.
Enter the exact milliamp value, read from an external meter, into the
High Value
Actual
numeric inputs.
6.
Press the
High Value
(20mA)
Capture
button, to capture the current (un-calibrated value) into the
Raw
Capture
field.
7.
The new
Span
and
Offset
calibration settings will be automatically calculated. (See figure below).
8.
Press
Accept
to write these new calibration figures to the module.
9.
The Calibration Type will then change to User Calibration, to reflect the changes.
Figure 5.22 – User Calibration – Input
