Fluke PM3370B user manual 50Hz

4 - 58 HOW TO USE THE INSTRUMENT

The signal on channel 1 is a square wave. Consequently, there will be only two vertical levels to display.

The signal on channel 2 is a sine wave, which is now displayed as a function of the square wave on channel 1.

-Press the X SOURCE softkey so that ’line’ is

-Turn off channel 1.

12
CH1 200mV
CH2 1.00V	X=ch1

ST6739

Horizontal deflection is now obtained from the line voltage. On the screen channel 2 (sine-wave) is displayed against the line voltage. The signals on the horizontal deflection (line) and the vertical deflection (ch2) have different frequency.

-Vary the frequency of the generator to get an almost stable picture.

The displayed figure is called a Lissajous figure. This lissajous figure has 5 (60 Hz line) or 6 (50 Hz line) tops depending on the line frequency. The number tops multiplied by the horizontal (line) frequency results in the frequency of the vertical signal.

2

CH2 1V X=lne

ch1
ch2
ch3	2
ch4
line
50Hz	60Hz CH2 1V	X=lne

ST6006

If the generator is equal or close to the line frequency, the Lissajous figure is an ellips whose shape depends on the phase difference. Measuring phase difference using the X Deflection mode is one of the typical applications for this mode.