Tektronix 7853A, Инструкция по эксплуатации

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Operating Instructions—7B53A/7B53AN Operators
2. Take the reciprocal of the time duration to determine
the frequency.
Example. The frequency of the signal shown in Fig. 1-13
which has a time period of 0.5 millisecond is:
Frequency =
Risetime Measurements
Risetime measurements employ basically the same
techniques as time-duration measurements. The main differ­
ence is the points between which the measurement is made.
The following procedure gives the basic method of
measuring risetime between the 10% and 90% points of the
waveform. Falltime can be measured in the same manner on
the trailing edge of the waveform.
1. Connect the signal to be displayed to the input of the
vertical unit.
TABLE 1-2
Risetime Measurements
Vertical
display
(divisions)
10% and 90%
points
Divisions
vertically
between
10% and 90%
points
4 0.4 and 3.6 divisions
3.2
5 0.5 and 4.5 divisions 4.0
6 0.6 and 5.4 divisions
4.8
7
0.7 and 6.3 divisions
5.6
8
0.8 and 7.22 divisions 6.4
8. Adjust the horizontal POSITION control to move the
10% point of the waveform to the second vertical line of
the graticule. For example, with a five-division display as
shown in Fig. 1-14, the 10% point is 0.5 division up from
the start of the rising portion.
2. Set the Vertical and Horizontal Mode switches on the
indicator oscilloscope to display the plug-in unit used.
9. Measure the horizontal distance between the 10% and
90% points. Be sure the VARIABLE control is set to CAL.
3. Set the Volts/Division switch and the Variable
Volts/Division control of the vertical unit to produce a
signal an exact number of divisions in amplitude.
10. Multiply the distance measured in step 9 by the
setting of the TIME/DIV OR DLY TIME switch.
4. Center the display about the center horizontal
graticule line with the vertical unit Position control.
5. Set the MAIN TRIGGERING controls to obtain a
stable display.
6. Set the TIME/DIV OR DLY TIME switch to the
fastest sweep rate that displays less than eight divisions
between the 10% and 90% points on the waveform.
7. Determine the 10% and 90% points on the rising
portion of the waveform. The figures given in Table 1-2 are
for the points 10% up from the start of the rising portion
and 10% down from the top of the rising portion (90%
point).
Fig. 1-14. Measuring risetime.
1-17