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Hold the Current
Thermo Fisher Scientific
Chapter 6
The Current Output
The standard 4–20 mA output can be adjusted so the control room and
local display readings are identical. In order to do this and to check the
Output
connection, hold commands will be used to set the current output to
known value.
Note Reference
1. Hold the current output at 4 mA (DAC 8).
If the value is not 4 mA after executing this command, you can apply a
correction factor. First, determine the correction factor by dividing the
new value by the initial value. For example, if the current output is
3.98 mA, divide 4.0 by 3.98:
In this case, the correction factor is 1.005. Enter the correction factor
(DAC 053013).
Note The initial value in this formula is the measured value of the 4 mA
output when the correction factor is equal to 1.0.
2. Hold the current output at 20 mA (DAC 5).
If the value is not 20 mA after executing this command, you can apply
a correction factor. First, determine the correction factor by dividing
the new value by the initial value. For example, if the current output is
20.04 mA, divide 20.0 by 20.04:
In this case, the correction factor is 0.998. Enter the correction factor
(DAC 052013).
Note The initial value in this formula is the measured value of the 20 mA
output when the correction factor is equal to 1.0.
3. Hold the current output at 12 mA (DAC 2).
Chapter 2
for instructions on how to use a DAC.
4.0/3.98 = 1.005.
20.0/20.04 = 0.998.
SGD-O User Guide
6-1
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