Introduction and application of neon tube type test pen
1. Neon tube test pen
The neon tube type test pen, also known as the electric pen, is used to test whether the metal casing of the wire, electrical appliance and electrical equipment is charged. The neon tube type tester is the most commonly used tester. When testing, it is determined whether the test object is charged according to whether the internal neon tube emits light.
This kind of electric pen mainly has two forms: pen type and screwdriver type. The ordinary electric test pen can detect the voltage in the range of 60 ~ 550v. In this range, the higher the voltage, the brighter the neon tube of the test pen. No light, for the sake of safety, don't use ordinary test pencils to detect voltages higher than 500v.
The use of neon tube type test pen
1. Distinguish direct current and alternating current. When measuring a charged object, the two electrodes of the neon tube emit light at the same time, indicating that it is alternating current. Only one of the two electrodes emits light, which is direct current.
2. Distinguish live wire and neutral wire. When measuring alternating current, the neon tube that lights up is the live wire, and the one that is not lit is the neutral wire.
3. Determine the positive and negative poles of direct current. Connect the test pen to the DC circuit for testing, the pole that glows on the neon bulb is the negative pole, and the pole that does not shine is the positive pole.
4. Judgment that the zero line is open. When the electric pen touches the two electrodes of the lamp socket, the neon tube will glow, but the bulb will not light up, indicating that the neutral wire is broken.
5. Measure whether the live wire touches the case. Test the casing of the electrical equipment, and the neon tube glows, indicating that the live wire has touched the casing of the equipment.
6. Judge the voltage level. During the test, the higher the measured voltage, the brighter the light emitted by the neon tube. Experienced people can judge the approximate voltage range according to the intensity of the light.
7. Determine the presence or absence of voltage. When testing the object under test, if the neon tube of the test pencil lights up, it means that the object under test has voltage, and the voltage is not lower than 60v. Test the metal shells of electrical equipment such as motors, transformers, electric tools, washing machines, and refrigerators with a test pen. If the neon tube lights up, it means that the shell of the equipment is charged.
