How to use non-contact voltage testers in your car?


Convenient and indispensable device

The modern world does not cease to amaze people with the variety of gadgets. Today we will talk about special device that allows you to check the voltage in the car or even at home. This indispensable device is called a non contact tester of voltage and any driver or auto enthusiasts should have this device with him. The non contact voltage tester allows you to check the voltage absolutely anywhere, since it is quite small. It is convenient to use and does not require much effort to use it. So, how to use non-contact voltage testers in your car?

What kind of device is it?

Voltage tester is a device that is designed to measure voltages in various places. With it, you can check the voltage at the outlet or in the car generator. The simplicity of design and ease of use of this device determines its popularity. Now it’s used not only by electricians whose work is directly related to voltage testing and electricity generally. For now, almost every toolbox of a real man should be equipped with this device.

In addition, modern contactless voltage testers not only serve to measure the voltage in the network, they can also be used to check the resistance of the network, and show the strength of direct and alternating current.

Types of Contactless Voltage Testers

Voltage testers differ in functionality and versatility. Basically, they look the same and it will be quite difficult to confuse this device with another. An elongated device, a bit like a pencil, showing the voltage in the network in volts – a typical contactless tester looks just like that.

In addition, contactless testers may vary in sensitivity to voltage. The optimal sensitivity of the tester is 90-1000 V. This will be enough to check the voltage both in the car and for working with the tester at home. The frequency of testers can also vary, but basically it is 50-60 Hertz.

How does it work?

Now you need to deal with one of the most interesting and important questions. How does this wonderful non-contact voltage tester work? How can I find out the voltage without touching the bare part of the electrical system?

In fact, the answer to this question is simple enough for those who are at least a little versed in the physical properties of charges and electrical circuits in general.

As you probably know, any closed system with alternating current is the creator of the electric field that is around the system itself.

Suppose it is, but how does it help? Our miracle device captures changes in the electric field around such systems and other objects through which current flows. In addition, the person who holds the tester in his hands is a kind of grounding.

To fully understand this phenomenon, you first need to understand how the capacitor works, which is available in any standard voltage tester.

Look, a person who holds the voltage tester in his hands is a kind of conductor. In addition, the earth, which a person touches the sole of his shoes is the second conductor. Between the two conductors there is a space, for example, the same sole of a shoe or a carpet that does not conduct current or any other dielectric. This circuit is the simplest circuit of any capacitor: two conductors of electric current between which there is any dielectric.

In the same way, connection appears between the wire or generator of the machine and the tip of the tester. The tip and the wire are two conductors of current, and between them, air that does not conduct electrical current it is a dielectric. So when the tester finds the presence of alternating current, it also indicates the presence of alternating voltage.

See also: Best Car Batteries

It sounds complicated enough, so let’s deal with everything in practice.

non-contact voltage tester in use - photo

How to work with a contactless voltage tester?

As mentioned earlier, a non-contact voltage tester is an indispensable thing in everyday life that thousands of people use daily to check voltage in various places.

What is needed in order to check the voltage? It should be noted right away that a non-contact voltage tester is the safest way to check voltage. This is because to check the voltage with it, you do not even need to touch the bare part of the wire. It is only worth bringing it to a close distance and it will immediately show if there is a voltage in the network or if it is absent. There are devices that show the exact voltage, their price is much higher than those that have an LED indicator. In the case of devices in which there is an LED indicator, it lights up if there is voltage in the network. If there is no voltage, accordingly, nothing will happen. There are also testers that, in addition to illuminating the indicator, emit a signal indicating that the electric field around the conductor is present and, accordingly, the voltage is also present.

In addition to the fact that this device is the safest of all, it is also the simplest. In order to determine the voltage, it is not necessary to bare the wires. Using a contactless tester, you can check the voltage even in insulated wires.


The main factors regarding contactless testers have been indicated, but what can be said in conclusion? I would like to say that a simpler and more convenient device for checking the voltage cannot be found. This is the most convenient option for those who have been looking for a device for a long time that would help him in this matter. The simplicity of design and use of such contactless testers also determines their durability.