Can a Voltage tester pen distinguish between alternating current and direct current?
Theoretically, it is possible, but the general commercial test pen does not have this function. Because it is not necessary. But if the subject has this need, you can use an ordinary multimeter to achieve this function. The specific method is - the multimeter is turned to the gear for measuring the voltage, and it is as high as possible. If the gear is too high, the reading will be inaccurate, and if the gear is too low, it is easy to get an electric shock. Then, hold the tip of the test lead with one hand, and the other test lead touches the detection point. If it is DC, you can naturally check the voltage with the DC gear, and the specific value can only be referred to. But the polarity can still be detected. If it is communication, it can only be detected with the AC file. Of course, in most cases, AC is mixed with DC, and both gears can be detected. This is also the reason why no manufacturers produce DC test pens.
