How to use the test pen
Commonly used low-voltage test pen, master the two-grip test method. Pen-type test pen, the palm touches the metal clip. Thumb index finger and middle finger, pinch the middle of the pencil holder. Rotary chisel-type test pen, the index finger presses the metal cap on the tail. Thumb, middle finger, ring finger, pinch the middle of the plastic rod. The neon tube small window is backlit, and you can observe it towards yourself.
Precautions for the use of the induction test pen
1. Before using the test pen, first check whether there is a safety resistor in the test pen, and then visually check whether the test pen is damaged, whether it is damp or water, and can only be used after passing the inspection.
Principle: There is a resistance in the test pen, and there is a light-emitting body - a neon tube. The key lies in the neon tube. After the resistance is reduced, there is a voltage to one end of the neon tube, forming a high potential. Your hand needs to touch the metal end of the end of the electric pen. , now you are the ground wire. There are two thin metal wires in the neon tube, which are very close but not connected. The neon tube is naturally filled with neon gas, and a suitable potential difference can generate a glow discharge. If the voltage is too high, it will break down the neon tube instantly. At this time, the neon tube will act as an insurance and will not cause too much damage to you. The low voltage will be more dangerous, because the traditional electric pen, the neon tube electric pen, will only work when it is above 100V. It will light up, don't be careless, and don't let water into the electric pen, otherwise you will know the feeling of electric shock.
2. When using the electric test pen, do not touch the metal probe at the front of the electric test pen with your hands. Doing so will cause an electric shock accident.
3. When using the test pen, be sure to touch the metal part of the end of the test pen with your hand, otherwise, because the charged body, the test pen, the human body and the earth do not form a circuit, the neon bubble in the test pen will not emit light, resulting in misjudgment. A charged body is not charged, which is very dangerous.
4. Before measuring whether the electrical equipment is electrified, first find a known power source to test whether the neon bulb of the electric pen can emit light normally, and it can be used normally.
5. When testing a charged body under bright light, special attention should be paid to whether the neon bulb really glows (or not), and if necessary, you can use another hand to block the light to make a careful judgment. Don't make a misjudgment, judge that the neon bulb is not emitting light, and judge that there is electricity as no electricity.
