In order to measure the "on" and "off" durations (points 1 and 2 in Fig. 5), the switching time (points 3, 4 and 5 in Fig. 5) is established, and the brightness is equal to the average brightness between the two. Minimum and maximum luminance values (llow and Lhigh in Fig. 5). The "on" duration is between points 3 and 4, and the "off" duration is between points 4 and 5.

1 "on" duration l brightness

2 "off" duration La average brightness

3 turn on time Lhigh maximum brightness

4 off time low minimum brightness

5 next connection time t time

The equivalent frequency (in Hertz) shall be obtained from the duration (in seconds). For pulse width modulation backlight, the influence of backlight change should be considered (for example, trigger oscilloscope). Alternatively, these measurements should be made with a continuously stable backlight.