Electrogram pen working principle and precautions for use - Solutions - Huaqiang

Spot Remarks 2017+

Test - lowercase jpg

Kaixin micro test

Test probe P100-M3

The working principle of a standard low-voltage voltage detector is based on the detection of electrical potential. When testing a live conductor, the metal tip of the device touches the charged object, and the user holds the back end, which usually has a metal hook or contact point. This creates a current path that flows through the detector’s internal components, including a gas-filled tube (like a neon lamp), resistor, the human body, and finally to the ground. This loop allows the tube to light up, indicating the presence of voltage. A voltage difference of at least 60 volts is typically required for the detector to glow. If the tube doesn’t light up, it means the object is not energized. In AC systems, both ends of the tube will light up, while in DC systems, only one end will illuminate. This helps users distinguish between AC and DC sources. When using an electric pen, there are several important precautions to follow: 1. Distinguish between leakage and static electricity. Some equipment may have ungrounded metal parts that can cause false readings. A trained electrician can use other tools like a multimeter or megohmmeter to verify whether the charge is due to leakage or static. Using the pen itself, if the tube flickers briefly, it indicates static; if it glows steadily, it suggests a real electrical leak. 2. Use the correct technique. Hold the pen with your thumb and middle finger, keeping the viewing window facing you. Place your ring and little fingers on the palm for stability. Touch the device under test with the tip. If the tube lights up, the device is energized, and the brightness corresponds to the voltage level. If no light appears, the device is not charged. 3. Stick to the rated voltage range. Standard detectors are designed for voltages between 60V and 500V. Testing below 60V may lead to inaccurate readings, while testing above 500V can be dangerous and may result in electric shock. Always ensure the device is used within its specified limits. 4. Prevent electric shocks and short circuits during testing. Avoid touching both conductors at once, especially when dealing with closely spaced terminals. Always maintain a safe distance and use proper insulation. For screwdriver-style pens, cover the non-conductive part with an insulating sleeve, leaving only about 10 mm of metal exposed. Electricians should wear insulated shoes and stand on insulating materials like wooden boards to reduce the risk of electric shock. By following these guidelines, users can safely and effectively use low-voltage voltage detectors in various electrical environments.