IOtech MultiScan 1200, User Manual

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232 Chapter 14: System Calibration TempScan / MultiScan User's Manual
These multiple channel values are indicated in the third table. Make sure that the channels selected
with the calibration command matches the channels connected to the precision thermocouple-
calibration source.
Note: The following text discusses the traditional manual method of calibration. But if you have
access to a PC with Windows 3.X or Windows 95, we strongly suggest using ScanCal. For
information on the software-automated method of calibration using ScanCal, see chapter
ScanCal .
CAUTION CAUTION CAUTION CAUTION
Scanning card calibration requires the use of a calibrated master unit chassis.
Calibration of Thermocouple Scanning Cards
Note: Prior to each calibration session, disable calibration protection by setting the rear panel DIP
microswitch 9 to the up (
1 ) position. Then enable Calibration Mode via the Enter Calibration
Mode (
K
) command with a valid password. If the default calibration password has not been
changed, enter
K12345
.
Note: At the end of each calibration session, disable Calibration Mode with the End Calibration
Mode (
E
) command. Then re-enable calibration protection by resetting DIP microswitch 9 to
the down ( 0 ) position.
To Calibrate a Thermocouple Card for Offset
1. Connect a Copper Short to Channel 1 on the scanning card being calibrated. Use standard copper
hookup wire.
Do not use thermocouple wire. Slide the scanning card into the previously-
calibrated master chassis.
2. Power up the unit and wait at least one hour before continuing.
3. Send the Calibrate Channel Offset (
H
) command
Hchan
– where
chan
refers to the first channel
number on the scanning card being calibrated (refer to the previous table for valid offset channel
numbers) – and wait for the command to complete. The
TRIGGER LED indicator will flash for a
few seconds.
4. Monitor the Calibration Status Register (
CSR
) to ensure that the Calibrate Channel Offset (
H
)
command completed without error. Refer to the User Status (
U
) command
U2
to monitor and
decode the Calibration Status Register (
CSR
).