User manual

58
UNI-T
®
UT4000 User Manual
8. Adjust the vertical scale and vertical position knob to achieve the best result of
waveform.
9. Using the elliptic oscilloscope display graph to observe, measure and calculate the
phase difference. (See the figure below)
Figure 3-7
If sin θ = A
or C
B D ,
θ is the angle of disparity between the channels. For definitions of A, B, C, D see the
above figure. Calculating with this formula, the angle of disparity is
θ = ±arcsin (A
) or θ = ±arcsin (C ).
B D
If the elliptic main axis is within quadrants I and III, the angle of disparity should be
within quadrants I and IV, i.e. inside (0~ π
) or (3π ~ 2π).
2 2
If the main axis is within quadrants II and IV, the angle of disparity should be within
quadrants II and III, i.e. inside (π
~ π) or (π ~ 3π).
2 2
Furthermore, if the frequencies and phase differences of two signals being measured are
exact multiples, you can calculate the frequency and phase correlation between the two
signals.
The signal must be
in the centre