The measuring pen's interior structure and its potential for damage
If the resistance of the measuring pen is broken, what will happen to the measuring live wire? The probability of electric shock is relatively high, because whether it is a decrease in internal resistance or an open circuit, it can lead to misjudgment and live operation.
Internal composition of the measuring pen
The structure of traditional electric measuring pens is very simple, consisting of high resistance resistance, neon bubbles, springs, and pen caps. The neon bubbles do not emit light under low voltage and usually only light up at 100V or above. It is difficult to damage them unless they are hit.
There are various resistance values for high resistance resistors. Theoretically, a resistance value greater than 500k ohms can meet the demand. However, we hope that the larger the resistance value, the better. Of course, it cannot be infinitely large, so it is an open circuit. When measuring charged objects, it does not emit light, which can easily lead to misjudgment. Therefore, the electric pen needs to be regularly checked and maintained.
So what happens if the resistance inside the stylus is lower than the set value? It is obvious that the human body is prone to electric shock when an electric pen comes into contact with a charged object. I believe everyone, especially electricians, have learned this lesson.
Hazards of damage to measuring pens
The misjudgment caused by infinite resistance may lead us to believe that the electrical appliance is dead and poses a risk of electric shock during maintenance operations, causing significant personal injury.
A measuring pen with a resistance lower than 500k ohms can cause a tingling sensation when measuring charged objects. If the resistance value is lower, it is equivalent to touching the live wire with your hand, and the consequences are very serious.
summary
When purchasing a test pen, you can bring a multimeter to check the internal resistance value, which is generally above the M Ω level. This indicates that the quality is excellent and can be used for a long time.
