The meaning of oscilloscope probe ×1 and ×10
On a general oscilloscope probe (similar to the probe of a multimeter), there is a small switch for selecting between ×1 and ×10. When selecting the ×1 level, the signal enters the oscilloscope without attenuation. When selecting the ×10 level, the signal is attenuated to 1/10 and then sent to the oscilloscope. Therefore, when using the ×10 level of the oscilloscope, the reading on the oscilloscope should be expanded by 10 times (for some oscilloscopes, you can select the ×10 level on the oscilloscope side to use it with the probe. In this way, after the oscilloscope side is also set to ×10 level, Just read it directly). When we want to measure a higher voltage, we can use the ×10 function of the probe to attenuate the higher voltage before entering it into the oscilloscope.
In addition, the input impedance of the ×10 gear is much higher than that of the ×1 gear, so when testing signal waveforms with weak driving capabilities, setting the probe to the ×10 gear can provide better measurement. However, it should be noted that when the level of the signal voltage is not clear, you should also measure it with the ×10 level first. After confirming that the voltage is not too high, you can then choose the correct range level for measurement. It is necessary to develop this habit, otherwise, If one day the oscilloscope is damaged because of this, it will be too late to regret it.
People often ask, why can't I see the waveform on the crystal oscillator pin with an oscilloscope? One possible reason is that the ×1 gear of the probe is used, which is equivalent to a very heavy load (an oscilloscope probe using the ×1 gear has a capacitance of hundreds of pF) is connected in parallel to the crystal oscillator circuit, causing the circuit to stop oscillating. . The correct method should be to use the ×10 gear of the probe. This should be noted during use. Even if the oscillation does not stop, the real waveform may not be visible due to excessive changes in oscillation conditions.
