How to measure a signal using an oscilloscope for the first time (Basics for newbies)

Some people may be confused by a bunch of theoretical knowledge when using an oscilloscope for the first time, and thus lose interest in learning. If we can first learn how to measure a simple signal, quickly get started and gain a sense of accomplishment, we may be more motivated to learn and understand the oscilloscope. Based on this idea, before learning some theoretical knowledge, we can first look at how to use an oscilloscope to measure a simple signal.

Tools:

Oscilloscope, probe

Step 1: Turn on the oscilloscope and connect the probe to it.

Step 2: Find the square wave calibration signal output terminal of the oscilloscope

Step 3: Hook the probe tip to the calibration signal output terminal and the probe ground clip to the ground terminal.

After the connection is completed, the oscilloscope may display the following:

Hey, why is it different from what I imagined? Shouldn’t a square wave be like this:

Don't worry, step 4: press the auto button on the oscilloscope

OK, so we have successfully detected a signal:

Of course, you may think, this is too simple, just auto it? I want to adjust the waveform myself. Then let's talk about how to adjust it by yourself.

There are usually two reasons why the waveform display is abnormal:

The first reason is that the waveform display is too large to fit on the screen, or too small to be seen clearly.

Too large horizontally Too small horizontally Too large vertically Too small vertically

Let's see how to adjust it:

If it is too large in the horizontal direction, we need to reduce it; if it is too crowded in the horizontal direction, we need to expand it. As shown in the figure below, you can touch the screen or turn the knob. The professional term for this button is time base, which controls the time of one grid on the horizontal axis.

If it is too big in the vertical direction, we need to reduce it; if it is too crowded in the vertical direction, we need to expand it. As shown in the figure below, you can touch the screen or turn the knob. The professional term for this button is vertical gear, which controls the voltage value of one grid on the vertical axis.

After you adjust the time base and vertical scale, you may find another problem: the waveform keeps shaking left and right and is unstable, like this:

This is the second reason why the waveform display is abnormal: the trigger level is not adjusted to the appropriate position.

First, we click on the "Level" on the right side of the waveform display area.

Then press your finger on the black frame area and slide upwards

When the trigger level moves into the waveform, the waveform becomes basically stable.

Or you can achieve the same effect by turning the Level knob in the Trigger area

Of course, the prerequisite for a stable waveform is that the signal itself is periodic.

Try it yourself and you will have a better understanding of the whole operation. No matter what kind of waveform you are measuring, you can adjust the waveform to the appropriate position as long as you follow this idea.