Tektronix 2225, Operator'S Manual

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Applications
NOTE
You can achieve better accuracy by using the SEC/
DIV control or horizontal magnification to expand the
waveform transition so that it occupies from four to six
horizontal divisions between the 10% and 90% ampli­
tude points.
5. Measure the horizontal distance between the 10% and 90%
points (Figure 3-6, Points A and B) and calculate time duration
using the following formula:
horizontal SEC/DIV
distance x switch
Rise _ (divisions)______ setting
Time magnification factor
EXAMPLE: In Figure 3-6, the horizontal distance between the
10% and 90% amplitude points is 5 divisions, and the SEC/DIV
switch is set to 1 p,s per division. Horizontal MODE is set to X I.
Substituting given values in the formula:
Rise Time
= 5 d iv x 1 p-s/div =
5
^
Time Difference Between Pulses On Time-Related Signals
The calibrated sweep speed and dual-trace features of the 2225
allow measurement of the time difference between two separate
events. To measure time difference, use the following procedure:
1. Set the TRIGGER SOURCE switch to CH 1.
2. Set both input coupling switches to the same position,
depending on the type of input coupling desired.
3. Using either probes or cables with equal time delays, apply a
known reference signal to the CH 1 input connector and apply
the comparison signal to the CH 2 input.
4. Set both VOLTS/DIV switches for either 4-division or 5-division
displays.
5. Set VERTICAL MODE to BOTH; then select either ALT or
CHOP, depending on the frequency of the input signals.
6
. If the two signals are opposite in polarity, set the middle VER­
TICAL MODE switch to CH 2 INVERT to invert the Channel 2
display.
3-10 2225 Operators