PeakTech 1215 Bedienungsanleitung Seite 137

6. Press the F3 menu selection button and choose XY for Format.
The oscilloscope will display the input and terminal characteristics of the network in the Lissajous graph
form.
7. Adjust the VOLTS/DIV and VERTICAL POSITION knobs, optimizing the wave form.
8. With the elliptical oscillogram method adopted, observe and calculate the phase difference (see Fig. 59).
Based on the expression sinq =A/B or C/D, where, q is the phase difference angle, and the definitions of A, B,
C, and D are shown as the graph above. As a result, the phase difference angle can be obtained, namely, q
=± arcsin (A/B ) or ± arcsin (C/D). If the principal axis of the ellipse is in the I and III quadrants, the
determined phase difference angel should be in the I and IV quadrants, that is, in the range of (0- π /2) or (3π /
2- 2π). If the principal axis of the ellipse is in the II and IV quadrants, the determined phase difference angle is
in the II and III quadrants, that is, within the range of (π / 2 - π) or (π- 3π /2).
The signal must be centered
and kept in the horizontal
direction.
Fig. 59 Lissajous Graph
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