Hitachi V-151F - Vertical Gain Calibration; 4. Applications; Rise;Fall Time Measurement

c. Adjust RVlll, for minimum trace shift when
rotation the V/DIV switch from 5mV to lOmV.
If necessary, rotate the vertical position
control to keep the trace in the center of
the screen.
(4) Vertical gain adjustment
Set the knob @ to lOmV/DIV.
Connect the CAL output to the INPUT
connector with probe.
Check - CRT display for five divisions of
deflection. Adjust the GAIN controls, RV143
for exactly five divisions of deflection.
4. Applications
4.1 Measurement of rise (fall) time
The measurement of the rise time of a pulse
requires not only the attention described above
but also attention to measuring errors.
The relationship between the rise time of a
measured pulse.
Trx and the rise time of an oscilloscope Tro
and the rise time shown on the screen surface
Trs is as follows:
Trx^ + Trs^ = Tro^
If the rise time of the measured pulse is suf
ficiently larger than that of the oscilloscope
(24ns for this oscilloscope), the error caused
by the latter on measurement may be ignored,
but if the latter approximates the former to a
marked degree, a measuring error is produced.
A true rise time is obtained by:
Trx = Tro2 - Trs^
Generally speaking, for circuit which produces
no waveform distortions, such as tilt, over
shooting, etc. the relationship between the fre
quency band and the rise time can be expressed
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