1. Ground the probe. If you can't see the horizontal line, please adjust the position knob of the oscilloscope to see if it is above or below the screen. If you don't look at the brightness, is it too dark? If there are no more, please report for repair;

The axis of ultrasonic emission is so thin that you can't see it. If you go from far to near, you may not find where the axis is.

It seems that this is a microwave problem. For ultrasound, I really didn't notice nodes and antinodes. Are you sure it's the ultrasound?

4. On the right is the X axis, which is also the time axis. If you are used to painting backwards, I have no problem, but I believe most people will not be used to it. 1, the sound velocity is measured by ultrasonic wave in general physics experiments in universities. Anyone who can think of a question will ask for an answer.

(4) Thinking about problems

1. If you turn on the power switch of the oscilloscope, neither the scanning line nor the light spot can be seen on the screen. What are the possible reasons? What adjustments should be made respectively?

2. Why did the receiver move away from the nearest transmitter?

3. If both the phase comparison method and the * * * vibration interference method are used to measure, when the phase of the transmitted signal and the received signal are the same, is the end face of the receiving end a node of vibration displacement?

4. The sine wave on the oscilloscope always "runs" to the right or "runs" to the left. Why?