CPT
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The Interface Solution Experts
PC-Programmable Signal
Isolater/Converter
Figure 6. PC Confi guration Software Trimming/Damping Tab
Trimming/Damping
To access the Trim feature, click the Trimming/
Damping tab . Trimming increases the measurement
accuracy of the parameter you are trimming by
either matching the reading of its actual input to its
scaling (Sensor Trimming) or calibrating the output
to the device receiving the output (Output Trimming).
Damping allows you to introduce a delay into the
response of your transmitter in order to stop short-
lived spikes from setting off alarms. Refer to Figure 7
for hookup.
Sensor Trim
Sensor Trimming increases the measurement
accuracy of your CPT by matching the reading of
its actual input to either a calibrated source or the
device to which it is connected. This verifi es that the
input from the sensor to the alarm is being interpreted
correctly.
The CPT can trim any point along the scale. Note
that one-point trimming applies an offset to the sensor
reading, while two-point trimming applies both an
offset and a gain.
Before you attempt to perform the Sensor Trim
function ensure that the Status section of the screen
indicates “Measurements On”. Sensor Trim can be
done only when the measurements are on. To do this
click the Mode dropdown box, from the menu bar, and
select “Measurements On”.
1. Select either one trim point or two trim points by
clicking the appropriate button. Each pair consists of
“trim” and “captured” values.
2. Enter the values that need to be trimmed into the
corresponding fi elds.
3. Apply the targeted signal to the input, wait until
it settles and click “Point 1 Trim” to capture the
measured value. If you chose “Two-point Trim” repeat
the step above for the second point and click “Point 2
Trim”.
4. To enable input trim and the values stored, click the
“Input Trim ON”.
