How to use test pen correctly
Electric test pen, referred to as electric pen, is a common tool used to check and measure whether low-voltage electrical conductors and electrical equipment shells are live.
The test pen is often made into a pen-type structure or a small screwdriver structure. Its front end is a metal probe, the rear plastic shell is equipped with neon bulbs, safety resistors and springs, and the tail end has a metal end cap or a pen-shaped metal nose, which is a metal part that must be touched by the hand when using it. The voltage range of ordinary electric test pen is between 60 and 500 volts. When it is lower than 60 volts, the neon bulb of the electric test pen may not emit light. If it is higher than 500 volts, it cannot be measured with ordinary electric test pen, otherwise it is easy to cause electric shock.
When the tip of the test pen touches the charged body, the voltage on the charged body passes through the tip (metal body) of the test pen, the neon bulb, the safety resistor, the spring and the metal body at the end of the pen, and then passes through the human body to connect to the earth to form a circuit. If the voltage between the charged body and the ground exceeds 60 volts, the neon bulb in the test pen will light up, indicating that the object under test is charged.
When using the test pen, you should pay attention to the following:
(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, whether it is broken, and can only be used after passing the inspection.
(2) When using the electric test pen, never touch the metal probe at the front of the electric test pen with your hands, otherwise, it 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. This will lead to misjudgment, thinking that the charged body is not charged, which is very dangerous.
(4) Before measuring whether the electrical equipment is charged, first find a known power source to test to check whether the neon bulb of the test pen glows normally. It can be used when it can emit light normally.
(5) When testing a charged body under bright light, special attention should be paid to whether the neon bulb really emits light (or does not emit light). Don't make a misjudgment. The neon bulb is judged to be not emitting light, and it will have electricity, and it will be misjudged as no electricity.
