What is the principle of operation of a test pen?
The principle of electropen detection for luminescence is that there is a certain potential difference between the charged body and the earth. When the potential difference exceeds a certain value, the neon bubble will emit light, and when it falls below a certain value, it will not emit light. The voltage measurement range of a regular low-voltage tester is generally between 60-500V, and neon bubbles below 60V may not emit light. When the voltage is higher than 500V, the low-voltage tester cannot be used for testing, otherwise insulation breakdown may occur, causing a risk of electric shock to the human body.
When standing on a stool or other insulator with a handheld electric pen to test the live wire, the large current will pass through the high resistance voltage reducing resistance rod inside the pen and become a weak small current. Then, it will pass through the neon bubble and the human body to discharge the surrounding environment. At this time, the neon bubble will emit light. However, there is no risk of electric shock in the human body at this time.
1. Before using the test pen, it is necessary to first verify its function to ensure that it is functioning properly. We can test on a known power source to check if the neon bubble is emitting light. We also need to check whether the test pen is damp or wet to ensure our own safety.
2. Before using a voltage tester to test the electric field, check if the voltage in the location is suitable. Do not attempt to test voltage higher than the applicable range with a voltage tester to avoid danger.
3. When using a test pen, do not touch the metal probe at the front end of the test pen with your hands to avoid electric shock accidents; When using a test pen, be sure to touch the metal plate or hook at the end of the test pen with your hand. If this is not done, although the neon bubble of the test pen does not emit light, because the charged body, test pen, human body, and earth do not form a circuit, it is not possible to correctly determine whether the charged body is charged. Once misjudged, it will be very dangerous.
4. When using a test pen in bright light, special attention should be paid to judging whether the neon bubbles of the test pen are really bright. Many accidents are caused by carelessness and misjudgment, and we must avoid this.
5. It is best to wear insulated shoes when using a test pen to prevent accidents before they occur.
6. When judging whether it is in phase or out of phase electricity, it is important to remember that both feet must be insulated from the ground. Test with both hands holding pens, whether both pens are bright or only one is bright, it is the same. Not bright is in-phase electricity, as long as it emits light, it is out of phase electricity.
7. When using a voltage tester to test high voltage equipment, the first step is to strictly follow the operation supervision system. While someone is operating, one person must be present for supervision. The operator should be in front and the guardian should be at the back. When using a test pen, it is important to pay attention to the compatibility between the rated voltage and the voltage level of the tested electrical equipment.
8. During electrical testing, operators must wear insulated gloves and insulated shoes to prevent contact voltage from harming the human body. The operator should first inspect the verification pen on the electric equipment. When conducting live testing on multi-layer circuits, the low voltage should be tested first, and then the high voltage should be tested. The upper layer should be tested first and then the lower layer.
