How to use a oscilloscope display the wave shape of AC power source?
1. Check the oscilloscope is connected with attenuator probes, and adjust to the right attenuation factor. 1x, 10x 100x, … the more big the number the more attenuator value

2. Adjust the oscilloscope to the relative measure scope and set to the right channel

3. Connect the ground with the clamp to the ground of the source

4. Use one probe connecting with zero line, the other connected with the supply line

5. Adjust the sample time to make the wave shape looks better

6. The noise pulses are displayed during my measurement result