What is the waveform refresh rate and is it important?

The oscilloscope's waveform refresh rate, also known as the waveform capture rate, is refresh rate = 1 (tacq+tdead).

With each sample, the waveform is captured by the ADC and processed internally. In general, the higher the refresh rate, the smaller the proportion of dead bands, and the more accurate the captured waveform.

However, the high waveform refresh rate brings the same flash memory capacity and storage depth to a smaller one.

The waveform refresh rate is relative to a digital oscilloscope. It takes time for a digital oscilloscope to sample and process data until it is finally displayed on the screen, and the time it takes to process the data is called dead time. The oscilloscope does not sample during the dead time, and the change in the signal cannot be detected, so in fact, not all waveforms can be seen by us, and the waveforms we see are actually divided into a period by the dead time, so there is a waveform refresh rate.

Sampling Time + Dead Time = Waveform Capture Period. The waveform refresh rate refers to the number of waveform captures in one second, which is the reciprocal of the waveform capture cycle. The longer the dead time in one second, the shorter the waveform display time will be, and the lower the waveform refresh rate, which will miss a lot of abnormal signals.

Therefore, the waveform refresh rate is useful for capturing abnormal signals with a low probability.

After the digital oscilloscope captures the waveform data, it needs to process and display the data, at this time the oscilloscope can not continue to collect data, the data of this time period will be lost, the waveform capture rate is to explain the number of times the oscilloscope captures the waveform in one second, the larger the value, the less likely the signal is to be lost, and the clearer the learning from this **:

The waveform refresh rate is an important technical indicator of the oscilloscope, which directly reflects the oscilloscope's ability to capture waveform details. The higher the waveform refresh rate, the shorter the dead time, and the higher the probability of catching abnormal signals. The figure below shows that the ZDS2022 desktop oscilloscope of Zhiyuan Electronics captures an abnormal signal with a low probability of occurrence, as shown by the dim waveform in the figure, and it is difficult for the oscilloscope with low refresh rate to capture such signals.

Hope it helps.

The waveform refresh rate is an important indicator of the oscilloscope, which together with the sampling rate directly reflects the oscilloscope's ability to capture the details of the waveform, and the mainstream oscilloscopes on the market are more than 10000wfms s (typical value). However, this metric is generally given by oscilloscope manufacturers, and few articles mention how to test this indicator, resulting in users not being able to really measure it. In this article, we'll introduce a simple method for getting a rough estimate of the oscilloscope's refresh rate. Reference.