The combination of sampling frequency and record length forms the time base of an oscilloscope. To setup the time base properly, the total measurement duration and the required time resolution have to be taken in account.
There are several ways to find the required time base setting. With the required measurement duration and sampling frequency, the required number of samples can be determined:
With a known record length in samples and the required measurement duration, the necessary sampling frequency can be calculated:
In the Multi Channel oscilloscope software, both record length and sampling frequency can be set independently, to give the best flexibility. They can be selected from menu's, using toolbar buttons but also keyboard short cuts are available, for more information, refer to:
The Multi Channel oscilloscope software also provides controls to change record length and sample frequency simultaneously to specific combinations to obtain certain time/div values: