Rigol DS1102/4B User Manual page 143

Ellipse method to observe the phase difference
SinT = A/B or C/D, where T = phase shift (in degrees) between the two signals.
From the formula above, you could get:
T = rarcsine (A/B) or rarcsine (C/D)
If the main axis of the ellipse is at I and III quadrant, T must be in the range of
(0~π/2) or (3π/2~2π). If the main axis is at II and IV quadrant, T must be in the
range of (π/2~π) or (π~3π/2).
© 2008 RIGOL Technologies, Inc.
Signal must be
centered in X
D
A
C
Figure 3-6
User's Guide for DS1000B Series
B
RIGOL
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