HP 120A - Page 28

Sect, n Page 12
INTERMEDIATE CALIBRATION
It may be desirable at times to set the calibra 
tion of the vertical amplifier at a known fraction
of its engraved calibration. To do so proceed
as follows:
1. Set VERTICAL SENSITIVITY switch to CALI 
BRATOR.
2. Adjust VERNIER control to obtain desired
fraction of normal six centimeter high square
wave. For example, in the illustration the pat 
tern is adjusted to be three centimeters high
thereby halving the sensitivity (multiply all of
the engraved calibration markings by two).
Note that basic calibration of oscilloscope has
not been disturbed. Original calibration may
be restored when desired by merely switching
VERNIER back to calibrated position.
Figure 2-10