Tektronix 7853A, Instruction Manual

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Operating Instructions— 7B53A/7B53AN Operators
Then, with a TIME/DIV OR DLY TIME switch setting
of 50 µs, the period of an unknown signal which completes
one cycle in seven horizontal divisions can be determined
by using the period formula (step 6):
9. Multiply the distance measured in step 8 by the
setting of the TIME/DIV OR DL Y TIME switch.
Period
(Seconds)
50 µs X 1.37 X 7 = 480 µs
Example. Assume that the distance between the time
measurement points is five divisions (see Fig. 1-13), and the
TIME/DIV OR DLY TIME switch is set to .1 ms.
Using the formula:
This answer can be converted to frequency by taking the
reciprocal of the period in seconds (see application on
Determining Frequency Measurements).
Time Duration =
horizontal
distance X
(divisions)
TIME/DIV OR
DLY TIME
setting
Substituting the given values:
Time Duration Measurements
To measure time between two points on a waveform, use
the following procedure:
1. Connect the signal to be displayed to the input of the
vertical unit.
2. Set the Vertical and Horizontal Mode switches on the
indicator oscilloscope to display the plug-in units used.
3. Set the Volts/Division switch of the vertical unit to
display about four divisions of waveform.
4. Set the MAIN TRIGGERING controls to obtain a
stable display.
Time Duration = 5 X 0.1 ms
The time duration is 0.5 millisecond.
Determining Frequency
The time measurement technique can also be used to
determine the frequency of a signal. The frequency of a
periodically recurrent signal is the reciprocal of the time
duration (period) of one complete cycle.
Use the following procedure:
1. Measure the time duration of one complete cycle of
the waveform as described in the previous application.
5. Set the TIME/DIV OR DLY TIME switch to the
fastest sweep rate that displays less than eight divisions
between the time measurement points (see topic entitled
"Time Measurements" and Fig. 1-8).
6. Adjust the vertical unit position control to move the
points between which the time measurement is made to the
center horizontal line.
7. Adjust the horizontal POSITION control to position
the time-measurement points within the center eight
divisions of the graticule.
8. Measure the horizontal distance between the time
measurement points. Be sure the VARIABLE control is set
to CAL.
Fig. 1-13. Measuring the time duration between points on a
waveform.
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