B Delay Time Position Control Settings - Tektronix 2235 Instruction Manual

Operating Procedures—2235 Operators
DIAL READING
AT POINT A
DIAL READING
AT POINT B
4207-24
Figure 4-14. B DELAY TIME POSITION control settings.
Rise Time
The measurement method for rise time Is the same as
for time difference between repetitive pulses, except that
the measurements are made between the 10% and 90%
points on the leading edge of the waveform. Fall time is
measured between the 90% and 10% points on the trailing
edge of the waveform.
/
y
--
1
The 10% point on the waveform intersects the center vertical
graticule line.
1
m
7
-
/
j'
h
:
The 90% point on the waveform intersects the center vertical
graticule line.
4207-25A
Figure 4-15. Rise time, differential time method.
1. Preset instrument controls and obtain a baseline trace.
2. Apply a 5-division signal to either vertical-channel
input connector and set the VERTICAL MODE switch to
display the channel used. Ensure that the VOLTS/DIV
Variable control is in the GAL detent.
5. Select ALT HORIZONTAL MODE and set the
B SEC/DIV switch to spread the rise-time-measurement
portion of the display as much as possible.
6. Select the B HORIZONTAL MODE. Adjust the
B DELAY TIME POSITION control until the display
intersects the 10% point at the center vertical graticule
line (see Figure 4-15, Point A).
NOTE
For rise time less than 0.2 iis per division, the
VOLTS/DIV Variable control may be used to obtain
an exact 5-division display.
3. Vertically position the trace so that the zero refer
ence of the waveform touches the 0% graticule line and the
top of the waveform touches the 100% graticule line (see
Figure 4-15).
7. Record the B DELAY TIME POSITION control dial
setting.
8. Adjust the B DELAY TIME POSITION control until
the display intersects the 90% point at the center vertical
graticule line (see Figure 4-15, Point B).
9. Record the B DELAY TIME POSITION control dial
setting.
4. Set the A SEC/DIV switch for a single-waveform
display. Ensure that the A and B SEC/DIV Variable control
is in the CAL detent.
10. Calculate rise time using the same formula listed in
the "Time Difference Between Repetitive Pulses" measure
ment procedure.
REV APR 1985
4-19