Series 3700 System Switch/Multimeter User's Manual
Section 6: Model 3750 Additional Information
3700S-900-01 Rev. C / July 2008
6-17
Preparing for calibration
Before performing the calibration steps, be sure that the Model 3750 is properly
disconnected from all external circuits. If an in-system DMM is to be used,
disconnect the external ABUS from other mainframes and instruments that
might be connected. If possible, disconnect all Model 3750 cables as well.
Excessive capacitance on the counter channels can cause that part of
calibration to fail. If a Model 3750-ST accessory is used, you can keep this
connected as long as external circuits are disconnected.
Prior to calibration, the channel must be unlocked for calibration.
channel.calibration.unlock(<ch_list>, <password>)
The actual calibration is performed in several steps. In each step, the hardware
outputs a value and expects a measured value to be entered. Once all the steps
are complete, the Model 3750 calculates new calibration constants to be used
until the next calibration takes place.
The following topics describe a list of steps to be performed to calibrate the
Model 3750.
Calibration steps for analog output channels
For DAC channels, a calibration sequence includes these steps:
1. Set Voltage, -12 to +12 range, generate Negative Point 1.
2. Send reading.
3. Set Voltage, -12 to +12 range, generate Negative Point 2.
4. Send reading.
5. Set Voltage, -12 to +12 range, generate Positive Point 1.
6. Send reading.
7. Set Voltage, -12 to +12 range, generate Positive Point 2.
8. Send reading.
9. Set Current, 0 mA to +20 mA range, generate Point 1.
10. Send reading.
11. Set Current, 0 mA to +20 mA range, generate Point 2.
12. Send reading.
13. Set Current, +4 mA to +20 mA range, generate Point 1.
14. Send reading.
15. Set Current, +4 mA to +20 mA range, generate Point 2.
16. Send reading.