HP 83487A User Manual page 52

Calibration Overview
User Calibrations—Optical and Electrical
The mainframe's CAL signal is a voltage source, therefore you can let the
instrument compensate for the actual characteristics of your probe by letting
the instrument calibrate to the tip of the probe. The instrument automatically
calibrates to the tip of the probe, sets the probe attenuation, and compensates
for any probe offset.
If you do not perform a probe calibration but want to use a passive probe,
enter the attenuation factor using the following steps:
1 Press the plug-in module's front-panel channel SETUP key.
2 Press External scale and then Attenuation.
You can use the probe calibration to calibrate any network, including probes or
cable assemblies. The instrument calibrates the voltage at the tip of the probe
or the cable input.
To calibrate an HP identifiable probe
1 Press the plug-in module's front-panel-channel SETUP key.
2 Press Calibrate and then Calibrate Probe.
To calibrate a non-identifiable probe
1 Connect the voltage probe to the plug-in.
2 Attach the probe tip to the CAL hook that is located near the floppy disk drive.
3 Press the plug-in module's front-panel channel SETUP key.
4 Press Calibrate and then Calibrate probe.
If the probe being calibrated has an attenuation factor that allows the instru-
ment to adjust the gain (in hardware) to produce even steps in the vertical
scale factors, the instrument will do so. Typically, probes have standard atten-
uation factors such as divide by 10, divide by 20, or divide by 100.
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