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.

1Connect a sine wave signal to channel 1, and a sine wave signal of the same frequency but out of phase to channel 2.

2Press the Autoscale key, press the Main/Delayed key, then press the XY softkey.

3Center 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):

sin θ

=

A

C

--- or ---

 

 

B

D

Signal must be centered in “X”

DA B

C

Example of centering a signal on the display

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Agilent Technologies 24A, 54621D, 42A, 54621A, 22A, 41A manual To use the XY horizontal mode