The structure of the traditional test pen is very simple. It consists of a high-resistance resistor, a neon bulb, a spring and a pen cap. The neon bulb does not emit light under low pressure.
The resistance of high-resistance resistors varies. In theory, more than 500k ohms can meet the needs. However, we hope that the larger the resistance, the better. Of course, it cannot be infinite. Let us have a misjudgment, so the electric pen needs to be checked and maintained frequently.
So what happens if the resistance in the pen is lower than the set value? Obviously, the human body is easily electrocuted when the electric pen touches the charged body. I believe everyone, especially electricians, have learned this lesson.
The danger of damage to the test pen
If there is a misjudgment caused by infinite resistance, we may think that the electrical appliance has no electricity, which will cause electric shock during maintenance operations and cause great harm to the human body.
When measuring a charged body, a test pen with a resistance of less than 500k ohms will make people feel numb. If the resistance is lower, it is equivalent to the hand touching the live wire, and the consequences are very serious.
