Agilent Technologies 54621A, Руководство пользователя

Страница: 183 / 276

5-13
Making Measurements
To use the XY horizontal mode
To use the XY horizontal mode
The XY horizontal mode converts the oscilloscope from a volts-versus-time
display to a volts-versus-volts display using two input channels. Channel 1 is
the X-axis input, channel 2 is the Y-axis input. You can use various transducers
so the display could show strain versus displacement, flow versus pressure, volts
versus current, or voltage versus frequency. This exercise shows a common use
of the XY display mode by measuring the phase difference between two signals
of the same frequency with the Lissajous method.
1 Connect a sine wave signal to channel 1, and a sine wave signal of the
same frequency but out of phase to channel 2.
2 Press the
Autoscale
key, press the
Main/Delayed
key, then press the
XY
softkey.
3 Center the signal on the display with the channel 1 and 2 position ( )
knobs. Use the channel 1 and 2 volts/div knobs and the channel 1 and 2
Vernier softkeys to expand the signal for convenient viewing.
The phase difference angle (
θ
) can be calculated using the following formula
(assuming the amplitude is the same on both channels):
Example of centering a signal on the display
θ
sin
A
B
--- or
C
D
---- =
A
B D
C
Signal must
be centered
in “X”