DPO3034 Acquisition Interval

I need more detailed info about the acquisition modes of this scope. I am reading the manual section on "How the Analog Acquisition Modes Work" and in the discussion about "Sample" mode it says "Sample mode retains the first sampled point from each acquisition interval. Sample is the default mode." My question: What is the "acquisition interval" and how does it relate to "Sample" mode and to "Hi Res" mode?

Hello!

A great resource here would be our XYZs of oscilloscopes primer (available here: https://www.tek.com/en/documents/primer/xyzs-oscilloscopes-primer-1), specifically the horizontal system controls and sampling controls sections starting on page 21.

Essentially what is happening here is that the ADC in your scope always operates at its maximum sample rate. When you set something lower than the maximum sample rate while the acquisition mode is set to sample, the scope decimates samples to achieve that setting. For example, if the max sample rate or your instrument is 1GS/s and you have 10MS/s set as your sample rate, the scope will decimate (throw out) 99 out of every 100 samples, leaving only the one required to show 10MS/s.

Hi Res deals with this differently. It will take a boxcar average of many of the samples that would have been decimated and treat those as your individual sample point for that interval. This can reduce noise significantly and is different than traditional waveform averaging because it can be used in a single acquisition on non-repetitive events.