• The calibrated time scales can be used to calculate the phase shift between two sinusoidal signals of the same frequency.
• If a dual trace or beam CRO is available to display the two signals simultaneously (one of the signals is used for synchronization), both of the signals will appear in proper time perspective and the amount of time difference between the waveforms can be measured.
• This, in turn can be utilized to calculate the phase angle θ, between the two signals.

Phase shift between two signals

Referring to the figure, phase shift can be calculated by the formula;

• Note that the calculation does not involve the actual calibrated timebase setting. In fact, the observed waveforms can be varied using the horizontal amplifier adjustment to obtain as many boxes for one full scale as desired.
• Another method for fast calculation is to multiply the scale factor by the phase difference (in cm) where the scale factor is degrees per box or degrees per cm.