Tektronix 5110, Инструкция по эксплуатации

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Operating lnstructions-51 10
11. Multiply the measured distance by the setting of
the Seconds/Div switch.
EXAMPLE: Assume that the Seconds/Div switch is set
to 50 µs and the horizontal distance between measure­
ment points is four divisions. Using the formula:
6. Set the Volts/Div switches and the variable Volts/Div
controls so the displays are equal and about five divisions
in amplitude.
7. Set the time-base triggering controls to obtain a
stable display. Set the Seconds/Div switch to a sweep rate
which displays about one cycle of the waveform.
Time
Delay
Sec/Div horizontal
- switch X distance = (50 µs) (4) = 200 µs
setting (divisions)
The time delay is 200 microseconds.
Multi-trace Phase Difference Measurement
Phase comparison between two or more signals of the
same frequency can be made using a dual-trace plug-in or
two single-trace
plug-ins. This method of phase difference
measurement can be used up to the frequency limit of the
vertical system. To make the comparison, use the follow­
ing procedure:
1. Set
the input coupling, switches of the amplifier
channels to either ac or de.
2. Set the Display switch on the time-base unit to either
Chop or Alt. In general, Chop is more suitable for low-
frequency signals and the Alt position is more suitable for
high-frequency signals. More information on determining
the mode is given under Vertical Display Mode in this
section.
3. Set the vertical plug-in triggering switches to trigger
the display on Channel 1 (or left plug-in) and Channel 2 (or
center plug-in).
4. Connect the reference signal to the Channel 1 input
connector and comparison signal to the Channel 2 (or
center plug-in) input connector. The reference signal
should precede the comparison signal in time. Use coaxial
cables or probes which have similar time-delay
characteristics to connect the signals to the input connec­
tors.
5. If the signals are of opposite polarity invert the
Channel 2 (or center plug-in) display. (Signals may be of
opposite polarity due to 180° phase difference; if so, take
this into account in the final calculation.)
8. Move the waveforms to the center of the graticule
with the vertical Position controls.
9. Turn the variable Seconds/Div control until one
cycle of the reference signal (Channel 1, or left plug-in)
occupies exactly eight divisions between the second and
tenth vertical lines of the graticule (see Fig. 1-8). Each
division of the graticule represents 45° of the cycle (360°
4- 8 divisions=45°/division). The sweep rate can be stated
in terms of degrees as 45 “/division.
10. Measure the horizontal difference between cor­
responding points on the waveforms.
11. Multiply the measured distance (in divisions) by
45°/division (sweep rate) to obtain the exact amount of
phase difference.
EXAMPLE: Assume a horizontal difference of 0.6
division with a sweep rate of 45°/division as shown in Fig.
1-8. Use the formula:
Phase horizontal
Difference = difference
(divisions)
sweep rate
X (degrees/= (0.6) (45°)=27°
division)
The phase difference is 27°.
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