Ask a professional to tell me how high the voltage will cause the step voltage to get an electric shock.

It means that two parts of the body should not touch the ground at a distance, not the toes.

First, let's look at how the voltage in the conductor is distributed.

Current can be simply compared to water flow. When water meets resistance when flowing, it will produce water pressure (both waterwheels and dams increase resistance to rivers to obtain useful water pressure). The same is true of current, and voltage will only be generated in a conductor with resistance.

Step voltage gets an electric shock, that is, an annular electric field is generated near the ground where the high-voltage line contacts. That is to say, there is a voltage distribution in which the radial voltage decreases around the contact point of the high-voltage line. It can be understood that the voltage at the center of the circle is equal to the voltage on the high-voltage line, and the farther away from the center, the smaller the voltage. Therefore, when a person strode from the vicinity of the center of the circle to the position far away from the center of the circle, the voltage on his two feet was different. In this way, this voltage will generate current through the human body, making people get an electric shock. The voltage between these two feet is related to the stepping distance: the greater the stepping distance, the greater the voltage difference.

Birds can't get an electric shock on high-voltage lines. In fact, there are two reasons: 1 is the reason for the low walking speed mentioned just now, and another reason is that the resistance of the high-voltage line itself is very small, so the voltage distributed on the high-voltage line is very small. It can be inferred that even if there is a distance of 1 meter between the feet of a bird, the voltage between them will not be very large (provided that other parts of the bird's body do not touch the ground, telephone poles and other zero potential points).

To sum up, the step voltage and the placement of voltmeter are two different things. The voltage measured by voltmeter is the voltage between its two electric pens, regardless of the placement position.