Use of Neon Tube Test Pens
1. Distinguish between 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 between live wire and neutral wire. When measuring alternating current, the neon tube is on the live wire, and the neutral wire is off.
3. Determine the positive and negative poles of direct current. Connect the test pen to the DC circuit to test, the neon bulb that glows is the negative pole, and the non-lighting pole is the positive pole.
4. Determine the zero line open circuit. When the electric pen touches the two electrodes of the lamp socket, the neon tube glows, and the bulb does not light up, indicating that the zero line is broken.
5. Measure whether the live wire touches the shell. Test the casing of the electrical equipment, the neon tube glows, indicating that the live wire has touched the casing of the equipment.
6. Determine the voltage level. During the test, the higher the measured voltage, the brighter the light emitted by the neon tube, and the experienced person 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 pen lights up, it means that the object under test has voltage and the voltage is not lower than 60v. Use a test pen to test the metal casings of electrical equipment such as motors, transformers, power tools, washing machines and refrigerators. If the neon tube lights up, it means that the casing of the equipment is charged.
