Calibration of rtd scanning cards, Caution – Measurement Computing TempScan/1100 User Manual
Page 129
TempScan / MultiScan User's Manual
879596
System Calibration 6-13
Calibration of RTD 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 an RTD Card for Offset
1. Connect a Copper Short to Channel 1 (across R1-, S1-, S1+, R1+) 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
).
To Calibrate an RTD Card for Gain
CAUTION
Ensure that the RTD scanning card has been calibrated for offset. If not, follow
the RTD card offset calibration procedure as described in the previous text.
1. Connect a precision 3-wire or 4-wire resistance source of
xxx.xx
ohms to Channel 1 on the scanning
card being calibrated. Slide the scanning card into the previously-calibrated master chassis.
2. Power up the unit and wait at least one hour before continuing.
3. Enter the Set RTD Gain Calibration Reference (
*G
) command
*Ggain
where
gain
is the appropriate
resistance value
nnn.nn
in ohms.
4. Send the following Calibrate Channel Gain (
G
) command
Gchan,type
– where
chan
refers to the
first channel number on the scanning card being calibrated (refer to the previous table for valid gain
channel numbers):
• 3-Wire RTD:
Gchan,16
• 4-Wire RTD:
Gchan,17
Wait for the command to complete. The TRIGGER LED indicator will flash for a few seconds.
5. Monitor the Calibration Status Register (
CSR
) to ensure that the Calibrate Channel Gain (
G
) command
completed without error. Refer to the User Status (
U
) command
U2
to monitor and decode the
Calibration Status Register (
CSR
).