Tektronix 1A1, Инструкция по эксплуатации, Страница: 25 / 137

Applications— Type 1A1
point you desire. Each cm on the graticule now represents
40° of 1 cycle (see Fig. 3-4).
6. Measure the horizontal distance, in cm, between cor­
responding points on the waveforms. Note the distance and
whether the Channel 2 waveform is leading or lagging (see
Fig. 3-4).
7. Multiply the distance by 4 0 °/cm to obtain the amount
of phase difference.
For more precise measurements, increase the previous
sweep rate, but do not change the setting of the oscillo­
scope Variable Time/Cm control. However, you must
consider this increase in your calculations.
For example, if you increase the sweep rate by a factor
of 5, and then measure the distance between waveforms,
each cm will represent 8° (40° -r- 5) of a cycle. Thus,
phase difference up to 80° can be measured more accu­
rately. When preparing to make the measurement, hori­
zontally position the waveforms to points where the grati­
cule markings aid in determining the exact distance. Fig.
3-5, for example, shows how the phase difference of the
Channel 2 waveform can be computed using this method.
3-5