13
4.3.2
CYCLE & FREQUENCY MEASUREMENTS
Shown in Fig 4-6, frequency measurements are made by measuring the time period of
one cycle of waveform (T), and calculating the frequency that equals the reciprocal of the time
period. For example, T=16
µ
S, then frequency is:
1
F =1/T = ------------------ = 62.5 KHz
16
×
10
-6
4.3.3 PULSE RISE TIME AND FALL TIME MEASUREMENTS
For rise time and fall time measurements, the 10% and 90% amplitude points are used as
starting and ending reference points.
(1)
Apply a signal to the input jack [19].
(2)
Use the VOLTS/DIV and VAR controls to adjust the waveform peak to peak height to
five divisions.
(3)
Adjust vertical position so that the tops of the waveform coincide with 100% point,
while the bottoms of the waveform coincide with 0% point.
(4)
Adjust Sweep switch to obtain the positive-going direction or negative-going direction
of the waveform on the screen.
(5)
Use the horizontal POSITION control to adjust the 10% points to coincide with a
vertical reference line.
(6)
Measure the horizontal distance in divisions between the 10% and 90% points on the
waveform (divisions).
(7)
Pulse rise time and fall time measurement is calculated by the following equation:
Horizontal distance (div)
×
sensitivity (Time/div)
Rise Time = -----------------------------------------------------------
Horizontal factor
For the example shown in Fig.4-7, the horizontal distance from 10% to 90% is 2.4
divisions, the sweep TIME/DIV setting is 1
µ
S/DIV, factor x 1. The rise time is
calculated as follows:
1
µ
S/DIV
×
2.4DIV
Rise Time = ------------------------------ = 2.4
µ
S
1
Fig. 4-7
10%
90%
100%
2.4DIN
Summary of Contents for AO-610
Page 1: ...Voltcraft AO 610 10MHZ OSCILLOSCOPE USER S MANUAL ...
Page 16: ...15 ...
