Sampling

What it does

Your PicoScope samples your measurements (i.e. it takes a series of single measurement values) at regular intervals to digitize and turn them into waveforms on your screen. PicoScope’s Sampling feature allows you to set either the total number of samples that make up each of your waveforms (Buffer memory prioritization) or the rate at which the samples are taken (Sample rate prioritization), depending on your preference.

When you prioritize Buffer memory you can choose from presets giving you a low, normal or a high number of samples or choose a custom target value. Likewise, when you prioritize Sample rate you can choose from presets giving you a slow, normal or fast sampling rate or choose a custom target value.

Sampling also lets you choose where to apply Progressive mode, which determines when the waveform is displayed (either after it has been captured in its entirety or as it is captured, bit by bit).

How it can help you

Waveforms can take many forms; their features can change slowly or quickly and they can cover either a long or short time span. When you're capturing waveforms, it's crucial to have the right settings to ensure you don't miss any important details.

Your timebase determines how long your capture is, while the Sample rate decides how much detail you capture. It's essential to find a balance: too short a timebase might cut off important parts of the waveform, whereas too long a timebase may mean you can’t see important detail; and too low a Sample rate may mean you don’t capture enough detail, whereas too high a sample rate might not add extra useful information, just taking up more memory and disk space.

PicoScope, a tool for capturing waveforms, helps with this balance using its Sampling mode priority feature. Here's how it works:

• If you need to see a consistent waveform over a longer time, prioritize Sample rate. This keeps the sample rate steady while increasing the timebase, resulting in more total samples.
• If you're dealing with different types of waveforms where detail becomes less important as time increases, prioritize Buffer mode. This keeps the total number of samples steady as the timebase increases, leading to a decrease in sample rate.

When you increase the timebase, it's more helpful to see waveforms forming on the screen instead of waiting for the entire waveform to be captured first. This way, you can catch important events and avoid capturing the wrong waveform. PicoScope's Progressive mode lets you choose the timebase value where the display switches from showing complete waveforms to showing them as they form.

How to use it

Click the Scope lozenge to open the Timebase panel, then click the Sampling tab to view the Sampling options.

Under Sampling mode priority, choose Buffer memory if, as you increase the timebase, you want to keep the number of samples constant or, alternatively, Sample rate if you want to keep the sample rate constant.

Use the Progressive mode control to increase or decrease the timebase value that determines when PicoScope transitions from displaying each waveform once it has been captured in its entirety to displaying it bit by bit as it is captured.