How to improve the test accuracy of phase difference?

When measuring the phase difference, if you want to measure accurately, you need to perform delay calibration between channels and delay calibration between probes. The ZDS2022 oscilloscope has an automatic channel delay calibration function, which will be automatically calibrated every time it is turned on. However, due to the influence of consistency (different manufacturers, different gears or processes, etc.), the external probe may have a little error. The delay calibration between probes can be done by simultaneously inputting a signal with a steeper edge (the rising edge signal can still be seen at the minimum time base), and then using knobs A and B to adjust the delay time of the corresponding channel (knob A for fine adjustment, knob B for coarse adjustment, the adjustable range is -100ns to 100ns), as shown in Figure 7.3, to align the rising edges of the waveforms of the two channels.

In addition, increasing the sampling rate can also help improve measurement accuracy. At a larger time base, the sampling rate may drop. In this case, the storage depth can be set to 112Mpts to increase the sampling rate.

Figure 7.3 Delay correction