by VirtinsTech » Wed Aug 28, 2019 10:39 am
Thank you for your questions.
In Multi-Instrument, the Oscilloscope, Spectrum analyzer, Spectrum 3D Plot, Multimeter windows (Views) have their own View Parameter Toolbars. These View Parameter Toolbars are overlapped and located at the bottom of the screen. If you click anywhere within the Oscilloscope window, its View Parameter Toolbar will be brought to front. The oscilloscope frame width (sweep time) selection box is located at the bottom left corner of the screen. Changing the oscilloscope sweep time will not change the sampling rate unless the hardware buffer size is exceeded. For VT DSO-2820E, the buffer size is 40k bytes. You can also change the oscilloscope sweep time by changing the Record Length (samples per oscilloscope sweep, or "Points", which is located at the upper right of the screen), if you "Enable Record Length change via 'Point' in Sampling Parameter Toolbar" via [Setting]>[Display]. In this way, you can enter the exact number of samples per oscilloscope sweep.
In many cases, you can set the oscilloscope sweep time to its maxium under a particular sampling rate, and use the zooming function to check the details of the waveform.