Operation steps of oscilloscope probe self-calibration

I believe that for power supply engineers, the oscilloscope's credit is irreplaceable. Once the product has a problem, it needs to capture the waveform, capture the timing, and test the accurate value to help the engineer analyze, process, and talk about the waveform. How to make the test data accurate and reliable is very important. Accurate numbers can help us, but distorted waveforms and values can only mislead us.
In the power supply industry for so many years, the oscilloscope has been the right and left hand of an engineer. Since we often see that many small companies use oscilloscopes that are too low-end, low bandwidth, and low sampling rate, I think that the oscilloscope is simple to operate and can capture the waveform. There is no need to buy a good oscilloscope.
Even before using the oscilloscope, I did not prepare for the test. In fact, it is often this incorrect operation that causes the test results to be distorted and affects the analysis.
Many engineers directly pick up the probe to test, without checking whether the probe needs compensation or whether the oscilloscope needs calibration.
The oscilloscope needs self-calibration and probe compensation adjustment before using it. Performing this adjustment is to make the probe match the input channel. When operating the instrument for the first time and when displaying data from multiple input channels at the same time, you may need to calibrate the data in the vertical and horizontal directions to synchronize the time base, amplitude, and position. For example, calibration is required when there is a significant temperature change (>5°).
The operation steps of probe self-calibration are as follows:
1. Disconnect any probes or cables from the channel input connector. Ensure that the instrument is running and warmed up for a period of time. In the R File menu, select Selfalignment.

2. On the Control tab, click Start Alignment.

3, Ralignment state (overall calibration state) field. The results of each calibration step for each input channel will be displayed in the Results tab.
The operation steps of probe compensation adjustment are as follows:
1. Connect the oscilloscope probe to the channel and press the PRESET button on the front panel (in the setting area on the left panel)
Operation steps for self-calibration of oscilloscope probe
2, check the shape of the displayed waveform
Operation steps for self-calibration of oscilloscope probe
The above two points seem simple, but they are often overlooked by engineers. In order to make the measurement more, please be sure to pay attention to the inspection. These two calibration functions should be present in any oscilloscope.
Let me introduce to you the interaction between the power cord measurement and verification power supply and the environment in which it is used.
It should be noted that the power supply can be of any specification, from small fan boxes in personal computers, to engines of a moderate size to power equipment in factories, to large-scale power supplies that provide support for phone groups and server groups.
Each power supply has a certain influence on the input power supply (usually municipal power supply).
In order to determine the effect of plugging in the power supply, the power supply voltage and current parameters must be measured directly on the input power line.
Basic knowledge of power quality measurement
The quality of power supply does not solely depend on the power plant, but also depends on the design and manufacture of the power supply and the load of the end user. The power quality characteristics of the power supply determine the "health status" of the power supply.
The power cord in the actual environment will never provide an ideal sine wave, but there will always be some distortion and undesirable characteristics on the line.
The switching power supply brings a non-linear load to the power supply. Therefore, the voltage waveform and the current waveform are not exactly the same.
A certain part of the input cycle will absorb current and produce harmonics on the input current waveform. Determining the impact of these distortions is an important part of power engineering design.
In order to determine the power consumption and distortion on the power line, it is necessary to measure the power quality during the input phase.
Power quality indicators include:
1, real power
2. Apparent power or reactive power
3, power factor
4, crest factor
5, according to EN61000-3-2 standard for current harmonic measurement
6, total harmonic distortion (THD)