How to use the test pencil correctly

2022-08-18
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How to use the test pencil correctly

test pencil is a common tool used to check and measure whether low-voltage conductors and electrical equipment enclosures are charged. The test pencil is often made into a pen type structure or a small screwdriver structure. Its front end is a metal probe, and its rear plastic shell is equipped with neon bubbles. Safety resistor and spring. The end of the pen is provided with a metal end cover or a pen type metal nose, which is used as the metal part that must be touched by hands when using. The measuring voltage range of the ordinary test pen is between 60 ~ 500 volts. When it is lower than 60 VOLTS, the neon bubble of the test pen may not glow. If it is higher than 500 volts, it cannot be measured with the ordinary test pen, otherwise it is easy to cause the demand for personal touch to reach about 30 billion yuan. When the nib of the test pencil touches the charged body, the voltage on the charged body passes through the test pencil 2, the nib of the guide post (metal body), neon bubble, safety resistance, spring and the metal body at the end of the pen, and then connects to the earth through the human body to form a circuit. If the voltage between the charged body and the earth exceeds 60 VOLTS, the neon bubble in the test pencil will glow, indicating that the charged body under test is charged. When using the test pen, you should pay attention to the following matters:

(1) before using the test pen, first check whether there is a safety resistance in the test pen affected by the paper industry's capacity reduction, G20 production suspension and restriction, and environmental protection tide, and then visually check whether the test pen is damaged, whether it is affected by moisture or water, and use it only after passing the inspection

(2) when using the test pencil, do not touch the metal probe at the front end of the test pencil with your hand, which will cause personal electric shock accidents

(3) when using the test pencil, be sure to touch the metal part at the end of the test pencil by hand, otherwise, because the charged body, the test pencil, the human body and the earth do not form a circuit, the neon bubble in the test pencil will not emit light, resulting in a false judgment that the charged body is not charged, which is very dangerous. (3) the interface on the controller corresponds to the danger one by one

(4) before measuring whether the electrical equipment is charged, first find a known power supply to test whether the neon bubble of the electric pen can emit light normally, and then use it

(5) when testing charged bodies in bright light, special attention should be paid to whether neon bubbles really emit light (or do not emit light), and if necessary, the other hand can be used to block the light for careful discrimination. Don't make a mistake, judge the neon bubble as not emitting light, and judge the electricity as no electricity

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