The voltage test range of a voltage tester pen is generally 60 ~ 500 V.
A voltage tester pen consists of a metal probe at the tip, a resistor, a neon tube, a pen body, a viewing window, a spring and a metal cap at the rear end. When the voltage tester pen is used to test a live conductor, once a closed circuit is formed by the live conductor, the tester pen, human body and the earth, and the potential difference between the live conductor and the earth exceeds a certain value (e.g. 60 V), the neon tube inside the tester pen will light up (for both AC and DC potentials). This indicates that the tested object is live and the voltage exceeds a certain level.
When using a voltage tester pen, the human hand must touch the metal part at the rear end of the pen, not the metal probe at the front tip. Hold the viewing window of the neon tube away from direct light so that the red glow generated when detecting a live conductor can be clearly seen. After gripping the pen properly, touch the rear metal cap with the thumb and forefinger, bring the probe into contact with the test point, and observe whether the neon tube lights up. If the neon tube glows faintly, do not conclude that the voltage of the live conductor is low. The faint glow may be caused by dirt on the tester pen or the test point of the live conductor, or the measured point may be the ground wire of the live conductor. In such cases, clean the tester pen or select a new test point. Only after repeated tests where the neon tube remains off or barely glows can we finally confirm that the tested object is not live.
The operating method of the voltage tester pen is extremely important, and there are specific rules for gripping it. It is necessary to distinguish between correct and incorrect ways of using the tester pen. Testing live conductors with an improper grip may result in electric shock accidents, so extra caution must be taken.
