Measurement Computing TempScan/1100 - Manual (Page 121)

TempScan / MultiScan User's Manual 879596 System Calibration 6-5
To Calibrate the Master Chassis for Offset
1. For offset calibration, locate the calibration jumpers located in one corner of an appropriate scanning
card, remove the two calibration jumper caps and short the calibration jumpers using one of those
jumper caps, as shown in the figure. Slide the scanning card into the master chassis.
2. Power up the unit and wait at least one hour before continuing.
3. Send the Calibrate Channel Offset ( H ) command H0 – where channel 0 refers to the chassis – to the
unit, 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 ).
5. To monitor the chassis calibration voltage, configure a normal acquisition with Channel 3 set as
channel type 90. The input will be returned in Counts.
To Calibrate the Master Chassis for Gain
CAUTION
Ensure that the master chassis has first been calibrated for offset. If not, follow
the master chassis offset calibration procedure as described in the previous text.
1. For gain calibration, slide the scanning card out from the chassis, locate the calibration jumpers,
remove any calibration jumper caps, and connect clip leads from the precision voltage calibration
source, as shown in the figure. Use standard copper hookup wire. Do not use thermocouple wire.
Slide the scanning card into the master chassis.
2. Power up the unit and wait at least one hour before continuing.
3. Set the precision voltage source to -4.4 (negative) Volts DC.
4. Send the Calibrate Channel Gain ( G ) command G0,91 to the unit – where channel 0 refers to the
chassis, and channel type 91 refers to a reserved calibration type – and 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 ).
6. To monitor the chassis calibration voltage, configure a normal acquisition with Channel 1 set as
channel type 90. The input will be returned in Counts.
7. Next, set the precision voltage source to +4.4 (positive) Volts DC.
8. Repeat Steps 4, 5, and 6.