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
