Kenwood CS-5200 Series - Measuring P U L S E R I S E and F a L L Times

8 —10 measuring Pulse Rise and Fall Times
The rise (fall) time is found by measuring the time between 10% and 90% of the peak value.
For this purpose, the oscilloscope has additional graduations at 10% and 901
1) Apply the signal. Adjust the VOLTS/DIV and V. VARI controls so that the amplitude is
5 divisions. Set the H. VARI control to CAL. Press the x10 MAG switch if necessary.
2) Use the y POSITION control to move the waveform between 10% and 901 Then, move the
10% point to a vertical graduation line with the POSITION. Measure the horizontal
distance between the 10% and 90% points. The time is found from the horizontal
distance.
Rise time
3) When measuring high speed rise (fall) time, you must allow for the oscilloscope' s
inherent time factor. The true rise time for a measurement of 20 ns is found as
follows:
to = Vt
2
m—t
2
r tm: Actually measured value
tr: Oscilloscope's inherent rise time
= V20
2
-8. 8
2
= 18. 0ns [CS-5230, 5235]
However, this correction factor is not significant when the actually measured value is
above 30 ns.
• Cursor measurement [CS-5230, 5260, 5270]
(1) Carry out step 1 of observation with the scale on the CRT.
44
Adjust to the vertical scale
with • POSITION
Figure 18-1 Measuring Rise Time