How to use a digital screen to display a large number of electricity test pens
Neon bulb pen
The biggest feature of the neon bulb electric pen is that when the pen touches a charged object, the neon bulb will light up, and the tip of the pen is just a small screwdriver, which can also be used in emergencies. Now there are products on the market that are detachable and have dual-batch heads that can be replaced at will, which is very practical.
Instructions
Hold the entire part of the electric pen between your index finger and middle finger, press the metal at the back end of the electric pen with your thumb to get an electric shock, and lightly touch the charged object with the tip of the pen.
working principle
Using the human body as a circuit, it lights up when the voltage reaches the working voltage of the neon bulb.
Precautions
1. Before the electrical test, first confirm the quality of the electric pen on a live object to ensure there is no misjudgment.
2. When testing electricity, do not touch the metal part of the front end of the electric pen with your body to avoid electric shock.
3. Read the instructions carefully before use and pay attention to the measurement range. Some are 50v~500v, and some are 110v500v.
4. Pay attention to distinguish between AC and DC.
5. When in doubt, use a multimeter and don't take chances.
6. The body is insulated from the earth.
digital display pen.
A digital pen will display the voltage on the screen when measuring. Usually the largest number displayed on the screen of the pen is the measured voltage. But I always feel a little unreliable.
Instructions.
There are two test buttons on the pen, direct test and induction breakpoint test. When we use it, we only need to choose to touch these two buttons according to the purpose of our own testing.
Measure continuity.
This function is the advantage of digital display pens over neon bulb pens. When measuring, you need to disconnect the power supply, hold one end of the wire with one hand, touch the sensor button with your thumb on the other hand, and touch the other end of the wire with the bit of the electric pen. The light bulb lights up, indicating that the wire is connected.
Measure breakpoints.
This function is not easy to use, especially multi-core cables, which cannot be measured and are not sensitive.
Although this kind of electric pen directly displays voltage, its accuracy is questionable. Many electrician friends reported that sometimes it is not accurate at all and even leads to misjudgment.
The light is too strong to see clearly, and the light is too dark to see clearly. The readings sometimes flicker on and off. This is its shortcoming. So I generally don't use digital pens.
Sound and light alarm sensor pen.
This kind of electric pen is a new product released in recent years. It is very convenient to judge whether an object is charged. It is also clear to distinguish the zero live line. It is not limited by ambient light factors. It is especially practical for measuring breakpoints. The disadvantage is that it does not display the voltage. At least so far, the one I use does not have this function.
This electric pen has a whole-body plastic casing to reduce the possibility of electric shock. It is super simple to use. When measuring, turn on the power first. Some of them just press and hold the power button. If the electromagnetic field is strong, the alarm will occur without touching the charged object, which also indirectly reduces the possibility of charging.
From personal experience, the above three types of electric pens have their own advantages, but they can only test whether an object is charged, and cannot accurately determine the voltage. When we need to measure the accurate voltage of a charged object, a multimeter is more reliable.
