Elenco 30MHz Dual Trace Manual do Utilizador descarregar pdf (Página 57)

APPLICATION

PULSE RISE TIME AND FALL TIME MEASUREMENTS

(Refer to Fig.13)

For rise time and fall time measurements, the 10% and 90% amplitude point are

used as starting and ending reference points.

1. Apply a signal to the input jack and set the CH 1/CH 2 switch to the channel to be

used. Use the VOLTS/DIV and VARIABLE controls to adjust the waveform peak

to peak height to six divisions.

2. Using the Y POSITION control, adjust the display so that the waveform is

centered vertically on the display. Set the sweep TIME/DIV control to as fast a

setting as possible while still being able to observe both the 10% and 90% points.

Set the VAR SWEEP control to the CAL position.

3. Use the X POSITION control to adjust the 10% point to coincide with a vertical

graduation line and measure the horizontal distance in divisions between the 10%

and 90% points on the waveform. Multiply this by the sweep TIME/DIV setting and

also by 1/10 if the X10 magnification mode was used.

NOTE:

Be sure that the correct 10% and 90% lines are used. For such measurements the

0, 10, 90 and 100% points are marked on the CRT screen.

The measurement is summarized by the following equation:

Rise Time = Hor div x TIME/DIV (x 1/10 if X10 is used)

For the example shown in Fig.13, the horizontal distance is 4.0 divisions. The

sweep TIME/DIV setting is 2μ s. The rise time is calculated as follows:

Rise Time = 4.0 (div) x 2 (μs/div) = 8 μs

Fig.13

Rise Time and

Fall Time Measurement

100

Rise time

Adjust to the vertical scale with POSITION

1 2 ... 52 53 54 55 56 57 58 59 60 61 62 ... 67 68

Sem comentários

Elenco 30MHz Dual Trace Manual do Utilizador Página 57