The main classification, purpose, and correct usage of voltage testers
1、 Neon tube type measuring pen.
The neon tube type measuring pen, also known as an electric pen, is used to check whether the metal casing of wires, electrical appliances, and electrical equipment is live.
This type of electric pen is divided into two forms: pen type and screwdriver type.
A regular measuring pen can detect voltage within the range of 60-550V. Within this range, the higher the voltage, the brighter the neon tube of the measuring pen. If it is below 60V, the neon tube will not light. For safety reasons, do not use a regular measuring pen to detect voltage above 500V.
The main uses of the neon tube type measuring pen are:
1. Used to distinguish between direct current and alternating current.
When the measured object is charged, both electrodes of the neon tube will light up simultaneously, indicating alternating current. If only one electrode lights up, it is direct current.
2. Used to distinguish between the live line and the zero line.
When measuring alternating current, the neon tube lights up with the live wire and does not light up with the zero wire.
3. Used to determine the positive and negative terminals of direct current.
When measuring direct current, the bright pole of a neon tube is the negative pole, and the non bright pole is the positive pole.
4. Used to determine the condition of zero line open circuit.
When the electric pen contacts both electrodes of the lamp socket, the neon tube emits light and the light bulb does not light, indicating that the zero line is broken.
5. Used to measure whether the live wire is touching the shell.
The electric pen tests the casing of electrical equipment. If the neon tube is lit, it indicates that the live wire has touched the casing of the equipment.
6. Used to determine the level of voltage.
When measuring with an electric pen, the brighter the neon tube, the higher the voltage. Experienced electricians can also determine the approximate voltage range based on the strength of the light.
7. Used to determine the presence or absence of voltage.
When measuring with an electric pen, if the neon tube is lit, it indicates that there is voltage present on the object on the side, and the voltage is not less than 60V.
Test the metal casing of electrical equipment such as motors, transformers, power tools, washing machines, and refrigerators with a test pen. If the neon tube lights up, it indicates that the equipment casing is live.
