The internal composition of the test pen, the damage of the test pen
What will happen to the live wire if the test pen's resistance breaks? Due to human error and live operation, whether due to an open circuit or a decrease in internal resistance value, there is a fair amount of chance that someone will experience an electric shock.
The test pen's interior structure
The classic test pen has a relatively straightforward design. It is made out of a pen cap, a spring, a neon bulb, and a high-resistance resistor. Under low pressure, the neon bulb does not produce any light.
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.
Summarize
When purchasing the electricity measuring pen, you can bring a multimeter to check the resistance value of the internal resistance, which is generally above the MΩ level, indicating that the quality is excellent and can be used for a long time.
