Is the ground binding post of an oscilloscope really grounded?

If so, is it grounded via the mains or neutral?

It should be noted that when measuring circuits that are not isolated from the mains (such as switching power supply primary measurement, electronic ballast, etc.), the ground wire needs to be connected in series with a capacitor before it can be connected to the circuit under test, and direct access will lead to a short circuit in the power supply.

The cause of the short circuit in the oscilloscope.

If you measure a waveform between two nodes, the ground wire on the probe may short-circuit the rest of the circuit behind the ground wire. This is because, in order to ensure electrical safety, the ground wire of most electronic instruments is connected to the safety ground wire by means of a power cable. The ground wires of oscilloscopes, signal generators, regulated power supplies, etc. are also connected to the safety ground, so the ground wires of these instruments are connected together during normal operation, (you can use a multimeter to measure it), if the ground wire of the oscilloscope is connected to other parts of the circuit, not where the ground wire of the signal source is connected, then part of the circuit will be short-circuited.

Dual-trace oscilloscope grounding considerations.

The dual-trace oscilloscope has two probes that can measure two signals at the same time, but the ground wires of these two probes are safely connected to the oscilloscope, so the ground wires of the two probes cannot be connected to two different points of a circuit at the same time, otherwise the two points will be electrically shorted through the oscilloscope probe ground.

When it is necessary to observe two signals at the same time, it is necessary to find the common point of the two measured signals on the circuit, connect the ground wire of one probe to this place, and connect the red wire of the two probes to the signal, that is, two signals can be observed on the oscilloscope at the same time without accidents.

Transformer grounding.

1: The transformer uses an isolation transformer, that is, the kind with two windings, in that case, if your system or board is not safely connected, the above situation will not occur, you can use a probe to measure the signal between any two points, but when the two probes are used together, you can only connect a ground wire clip.

2: The transformer is self-lotus, then it can not be connected randomly, pay attention to the measurement, especially when measuring the power supply, otherwise there may be a short circuit danger of the power live wire - oscilloscope ground wire - safety - zero line.

Safety grounding wire, mainly to prevent accidental electric shock.

Oscillograph. One of the probe heads is grounded, and the other is connected to the point where the waveform needs to be detected. The connection method in the figure does not really ground the probe head, resulting in the phenomenon of false ruler only grounding.

Generally, oscilloscopes have a self-calibrating signal that generates a typical sine wave by itself.

It is used to correct the accuracy and normality of the oscilloscope.

If the oscilloscope's probe is really grounded, clutter should not be visible on the display, otherwise there is a problem with the display.