6-21
Figure 6-24.—Period time of the waveform (TIME/DIV).
The potentiometer is labeled VAR, and the panel has an UNCAL indicator that lights when the VAR
control is in the variable position. When you desire to accurately measure the time of one cycle of an
input signal, turn the VAR control to the CAL position and turn the TIME/DIV switch to select an
appropriate time base. Suppose you choose the 10-microsecond position to display two cycles of an input
signal, as shown in figure 6-25. One cycle occupies 3 centimeters (small divisions) along the horizontal
axis. Each cm has a value of 10 microseconds. Therefore, the time for one cycle equals 30 microseconds
(3 10). Recall that the frequency for a signal may be found by using the following procedure:
