QUANTUM™ LX EVAPORATOR CONTROL PANEL
OPERATION
090.610-O (MAR 2016)
Page 61
CALIBRATION – Analog Output Calibration
DESCRIPTION: This screen is used to calibrate individual ana-
log outputs.
Use this screen if an analog output signal (channel) requires
calibration.
The QuantumTM LX analog outputs have a range of approxi-
mately 0 to 25mA, but most devices that are controlled require
a signal that varies between 4 and 20mA. To restrict the ana
-
log outputs to the proper values, each of the outputs must be
calibrated before they can be used. Every output channel has a
Top End and a Bottom End value that are used for calibration.
Both values can be set from 0% to 100%. The output channel’s
maximum value is represented by 100% and its minimum value
is represented by 0%. To calibrate the channel, the Top End per-
centage is decreased until the maximum output for the channel
is limited to 20mA. In addition, the Bottom End percentage is
increased until the minimum output for the channel is 4mA.
Below is a systematic procedure for calibrating one analog
output.
1. Congure the analog output channel for its intended
use. For example, if the channel is to be used for PID
control, enter the Device Source and Device Channel
of the selected analog output channel under one of
the PID columns on the PID Setup page.
2. Set a meter to read the channel output value in mil-
liamps.
3. Go to the Analog Output Calibration page.
4. Select the Analog Board and the Channel Number for
the output that is being calibrated.
5. After the Analog Board and Channel Number are se-
lected, the channel function will be displayed below
the Channel Number. If Not Congured is shown here
instead, the channel has not yet been assigned a con-
trol function. Return to step 1 and setup the channel
for the control task it is to perform.
6. Press [1] and the value shown on the meter should go
to the channel low-end value.
7. Check that the “Delta For Changing Output Percent-
age” value is 10.00. If it is not, press [0] until it is
displayed as 10.00.
8. If the channel output is greater than 4mA press [4].
If the channel output is less than 4mA, press [7]. Use
these keys to nd the output value closest to 4mA.
9. Press [0] once to decrease the “Delta For Changing
Output Percentage” value to 1.00.
10. Use the [7] and [4] buttons again to nd the value
closest to 4mA.
11. Repeat steps 9 and 10 for Delta values of 0.1 and 0.01
to bring the output value as close as possible to 4mA.
12. Press [3] and the value shown on the meter should
go to the channel high-end value.
13. Check that the “Delta For Changing Output Percent-
age” value is 10.00. If it is not, press [0] until it is
displayed as 10.00.
14. If the channel output is greater than 20mA press [4].
If the channel output is less than 20mA, press [7]. Use
these keys to nd the output value closest to 20mA.
15. Press [0] once to decrease the “Delta For Changing
Output Percentage” value to 1.00.
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