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(2) Cursor measurement (CS-5130 only)
1. In the same way as the ordinary measurement.
adjust
waveforms
to be measured
to an
easy-to-observe
position.
2. Set the cursor mode to AT.
3. Adjust the 4 REF cursor to the left edge of the pulse sig-
nal to be measured, and the A cursor to the right edge.
4. Measured value is displayed in the upper right part on
the screen.
Measured value
T
12.1us
4
8. PULSE
RISETIME
AND
FALLTIME
MEAS-
UREMENTS
(1) Ordinary measurement
For risetime and falltime measurements, the 10% and 90%
amplitude points are used as starting and ending reference
points.
Procedure:
1. Apply asignal to the INPUT jack. Set the vertical MODE
to the channel to be used.
Use the VOLTS/DIV and VARIABLE to adjust the wave-
form peak-to-peak height to five divisions.
2. Using the ¢ POSITION control and the other controls,
adjust the display such that the waveform is centered
vertically in the display. Set the SWEEP TIME/DIV to as
fast a setting as possible consistent with observation of
both the 10% and 90% points. Set the SWEEP VARIA-
BLE control to CAL position.
3. Use the <
POSITION control to adjust the 10% point
to coincide with a vertical graduation line and measure
the distance in divisions between the 10% and 90%
points on the waveform.
Multiply this by the SWEEP
TIME/DIV and also by 1/10, if ''x 10 MAG" mode was
used.
NOTE: The graticule on the CRT includes the 0, 10, 90, and
100% lines assuming that 5 divisions correspond to
100%. Use them as a reference for accurate meas-
26
urements.
Using the formula:
Risetime = Horizontal
distance
(div) x (SWEEP
TIME/DIV
setting)
x 'x 10 MAG"' value-1 (1/10)
Adjust to the vertical scale
with <
POSITION
Rise time
Fig. 30
[EXAMPLE]
For the example, the horizontal distance is 3.3 divisions. The
SWEEP TIME/DIV is 2 (us/div). (See Fig. 30)
Substituting the given value:
Risetime = 3.3 (div) x 2 (us/div) =6.6us
Risetime and falltime can be measured by making use of the
alternate step 3 as described below as well.
4. Use the <® POSITION control to set the 10% point to
coincide with the center vertical graduation
line and
measure the horizontal distance to the point of the in- ~
tersection of the waveform with the center horizontal
line. Let this distance be D,. Next adjust the waveform
position such that the 90% point coincides with the ver-
tical centerline and measure the distance from that line
to the intersection of the waveform with the horizontal
centerline. This distance is D2 and the total horizontal
distance is then D, plus D2 for use in the above relation-
ship in calculating the risetime or falltime.
Using the formula:
Risetime = (D; +Dg) (div) x (SWEEP TIME/DIV
setting) x''x 10 MAG" value—1 (1/10)
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