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What is a Non-Contact Voltage Tester and Do You Need One?

Do you know what a non-contact voltage tester is? Do it yourself (DIY) projects can be a lot of fun, but they can also be scary and downright dangerous if you don’t have the right tools or knowledge before you start.

 Non-Contact Voltage Tester

Take projects involving electrical work, for example, you don’t want to just start taking sockets and light switches apart without knowing which wires you’re safe to touch and which will give you a wild hairdo at the very least.

Today we’ll be looking at some of the options available for non-contact voltage testers and diving into what they are, if they’re safe, and what you should look for when purchasing one. We’ll even share our top three choices. So, keep on reading to learn how a voltage tester can help you with your next electrical project.

Top 3 Picks

Best Value – Sperry Instruments STK001 Non-Contact Voltage Tester/Outlet Tester Kit

With two tools giving a range of voltage detection applications and numerous features this durable, easy-to-use kit offers the best value for its price range.

Best Budget – Auroland Hanmatek Non-Contact Voltage Tester

This dual-range electric tester pen detects standard and low voltages and is suitable for an array of applications. With multiple functions and a durable design that won’t break the bank, it is the best budget option on our list.

Customer Choice – Fluke VoltAlert 1AC-II Volt Non-Contact Voltage Tester

The Fluke VoltAlert has the highest customer satisfaction of any tester on our list. Boasting a wide voltage detection range, superior ratings, and VoltBeat technology, it’s easy to see why this electric tester pen makes Customer’s Choice.

What is a Non-contact Voltage Tester?

It’s a tool that everyone should have in their electrical tool kit. A non-contact voltage tester (also known as an electric tester pen, or voltage tester) is a tool designed to safely detect voltage in an electrical connection without the need to come into direct contact with the source. With a red or green glowing tip and a beeping sound, a non-contact voltage tester provides a quick and reliable visual and audible alert if a voltage is present.

Non-contact voltage testers are useful for moving or reconfiguring light switches, electrical sockets, and other powered connections as well as troubleshooting problems in those same areas.

How Do Non-contact Voltage Testers Work?

Non-contact voltage testers have a sensor built into the tip of the tool that detects voltage when touching something like an outlet or power cord. The voltage that is detected is capacitively coupled from a live circuit to the voltage tester and back to the grounded reference, which is the person holding the tester. Once the voltage is detected, the tip of the tester will glow, and the tool will beep. Tools with dual-range functions typically have color-coded and sound-coded features that distinguish each range.

Types of Non-contact Voltage Testers

There are two types of non-contact voltage testers – inductively coupled voltage sensors and capacitive coupled sensors. Each works in vastly different ways and is suitable for different applications.

Inductively Coupled Voltage Sensor

These voltage testers use a magnetic field to detect if a wire or object has a current flowing through it. They will only work on objects that are conductive such as metal.

Capacitive Coupled Sensor

Capacitively coupled voltage testers measure electric field and can detect anything that acts as a dielectric material or conductive object.  These voltage testers are suitable for metal or non-metal objects.

What to Look For in a Non-contact Voltage Tester 

What to Look For in a Non-contact Voltage Tester 

There are several key features to consider when choosing a non-contact voltage tester. These features include:

Voltage Range Detection

If you intend to use your voltage tester for a range of applications, it is important to find one that measures high voltage alternating current (AC) as well as low voltage AC.

The high voltage range should be 48 V to 1000 V, while the low voltage range should be 12 V to 48 V.


Always ensure that the voltage tester you use is rated with an official organization’s measurement category from CAT I to CAT IV.

CAT IV is considered the highest safety classification.

The AC voltage listed directly after the tools CAT classification will indicate the maximum voltage rating that the tester can safely check. Never try to exceed these ratings.


Choose a voltage tester with the ability to adjust its sensitivity to suit the application you are working on and the environment that you are in.

If the tester is in a sensitive setting, you may inadvertently pick up electrical currents from locations other than the source you are working with. These could lead to false positives and potential safety risks. Being able to adjust the tool’s sensitivity will prevent this.


Non-contact voltage testers can come with a range of features that impact their function and usefulness in different applications. Some of these features include battery-check function, LED flashlights, laser pointers, and shirt clips. The more features your chosen voltage tester has, the more functional it will be.


You want to choose a voltage tester that is comfortable to hold and will not cause hand fatigue. This is especially important if you will be using the tester extensively.

An ergonomic and compact design will give you the most comfort and be the easiest on your wrist and hands.

The Best Non-Contact Voltage Testers

Klein Tools NCVT-2 Voltage Tester

Klein Tools NCVT-2 Voltage Tester

The Klein Tools NCVT-2 Dual-Range Non-Contact Voltage Tester detects a standard voltage (48-1000V AC) in things like electrical outlets, lighting fixtures and switches, cables, and circuit breakers, as well as low voltage (12-1000V AC) in things like entertainment, communication, and security systems. It has a CAT IV 1000 V rating giving it increased function and safety.

This lightweight tester is equipped with a powerful green LED indicator light that lets you know the tester is functioning properly and adds illumination to dimmer work areas. A flashing red light and one of two different warning sounds alert you to the detection of either standard or low voltage.

The NCVT-2 is made of durable polycarbonate plastic resin and runs on two AAA batteries. An auto-off feature extends the life of the batteries by shutting the unit off while not in use. This tester comes with a convenient pocket clip and a 2-year manufacturer’s warranty.


  • Detects standard and low voltage,
  • Excellent CAT rating,
  • LED indicator light,
  • Auto-off feature.


  • Does not detect current.

Fluke 1AC-A1-II VoltAlert Non-Contact Voltage Tester

Fluke 1AC-A1-II VoltAlert Non-Contact Voltage Tester

The Fluke VoltAlert 1AC-II Volt Non-Contact Voltage Tester has a detection range from 90 to 1000 V AC and a CAT IV 1000 V rating for extra function and safety.

This easy-to-use, pocket-sized tester lets you know when voltage is detected with a distinct beeping sound and glowing tip. And with Voltbeat technology and a continuous self-test feature, you always know when the tester is working or when the batteries need to be changed.

The VoltAlert 1AC-II runs on two AAA batteries which are included.


  • Excellent CAT rating
  • Self-test feature indicates tool is working.


  • Not dual range.

Sperry Instruments STK001 Non-Contact Voltage Tester

Sperry Instruments STK001 Non-Contact Voltage Tester

Sperry Instruments STK001 Non-Contact Voltage Tester / Outlet Tester Kit comes with the Sperry VD6504 Voltage Tester and the Sperry GFI6302 Outlet/Receptacle Tester.

The VD6504 Voltage Tester has a range of detection from 50 – 1000 V AC and is rated CAT III 1000V and IV 600V. The VD6504 is powered by one AAA battery and has an insulated probe tip which ensures you never contact live electrical wires. It is equipped with a self-test battery check feature that lets you know when the unit is working and when the batteries need to be changed. The detection of voltage is indicated with an audible beep and 360° visual glow.

The GFI6302 Outlet/Receptacle Tester indicates seven different wiring conditions and is rated CAT III 300V and C-UL US. There is an onboard wiring legend, and each condition is indicated by a color-coded neon light. It can test both standard 3-wire 120V and GFCI outlets and runs on one AAA battery.

Both testers have a high-impact resistant ABS body with rubber grips and are rated for 10-foot drops and 250-pound crushing weight.


  • Two tools provide more versatility,
  • Self-test battery check feature,
  • Extremely durable.


  • Not dual range,
  • Slightly lower CAT ratings than others on our list.

Southwire 40150N Advanced AC Non Contact Voltage Tester Pen

Southwire 40150N Advanced AC Non Contact Voltage Tester Pen

The Southwire 40150N Advanced Dual-Range Non-Contact Voltage Tester has two detection ranges – 12 to 1000 V and 100 to 1000 V and an IP67 rating making it dustproof and water-resistant.

This lightweight, electric tester pen indicates when voltage is detected with a beeping sound and red LED light. An integrated bi-color LED confirms the tester is operational and indicates with range is selected. The rugged design stands up to a 6-foot drop test rating and has thin probe tips specifically for wall outlets. It is powered by one AAA battery and has a built-in low battery self-test feature, so you always know if it is working.

The 40150N will not detect voltage if:

  • it is DC,
  • the user is not grounded,
  • the wire is shielded in a metal box or conduit,
  • the tip cannot be fully inserted into the outlet,
  • the outlet has a tamper-proof design,
  • the user’s hand is insulated from the tester,
  • the wire source is partially buried.

This multi-function tester comes with a high-powered, built-in forward/rear facing flashlight and pocket clip for ease of transport.


  • Dual range,
  • Dustproof and water-resistant,
  • Self-test feature,
  • Additional safety features,
  • More features than others on our list.


  • Not suitable for vehicle voltage testing
  • Cannot detect current.

Klein Tools NCVT-4IR Voltage Tester

Klein Tools NCVT-4IR Voltage Tester

The Klein Tools NCVT-4IR Non-Contact Voltage Tester is designed for HVAC applications and has a detection range from 12 to 1000 V. It boasts an Infra-red Thermometer that can be set to Degrees Celsius or Fahrenheit and can measure from -30 to 250 degrees Celsius (-22 to 482 degrees Fahrenheit).

This lightweight electric tester pen indicates voltage with visual and audible prompts and has a backlit LCD. The onboard laser pointer measures temperature of a specific surface. The unit is powered by two AAA batteries and has a convenient power-off function that extends the battery life. The NCVT-4IR is water and dust-resistant and easy to store.


  • Great for HVAC applications
  • Infra-Red Thermometer
  • Power-off function
  • Water resistant


  • Does not have a flashlight.

Auroland Non-Contact Voltage Tester

Auroland Non-Contact Voltage Tester

The Auroland Hanmatek Non-Contact Voltage Tester is equipped with two detection ranges – 12 – 1000 V and 90 – 1000 V.

This electric tester pen is lightweight and easy to store. It indicates the presence of voltage with audible and visual signals that are color and sound coded to distinguish different signal strengths.

The Auroland tester boasts durable construction and is powered by two AAA batteries. An integrated power-off function senses when the tester is not in use and shuts it off to conserve battery life. And a battery status indicator lets you know when the batteries need to be replaced.

The integrated nine-gear system lets you adjust the signal strength and LED digital display, and a built-in LED flashlight adds illumination to darker workspaces. This unit comes with a contactless stylus, user manual, and a 1.5 V AAA Battery.


  • Dual detection range,
  • Color and sound coded,
  • Power off function
  • Battery status indicator
  • Adjustable signal strength


  • Only detects AC.


Are Non-contact Voltage Testers Safe to Use?

Non-contact voltage testers are designed with safety in mind. They are insulated from electricity and are made to let you test for electric current without having to splice wires open or come into direct contact with potential currents.

How Do I Know If the Tester is Functioning?

If the voltage tester detects voltage, the tip will light up and a beep will typically be heard. But if this does not happen, it doesn’t mean there is no current. It may mean your tester is not functioning correctly.

Most non-contact voltage testers are equipped with self-testing functions that give you a constant display of how much battery life is left. This function allows you to know if the tester is working prior to performing a test.

Is a Voltage Tester the Same as a Multimeter?

Voltage testers and Multimeters are not the same tools. Non-contact voltage testers can only detect if a voltage is present or not. They do not give any other readings. They are typically shaped like a pen and have no additional parts.

Multimeters, on the other hand, give readings for AD and DC voltage, frequency, continuity, resistance, and electrical capacitance. These devices typically consist of an LED reader and two probes.


The overall function and design of non-contact voltage testers are similar but with different features and functions, we see they are not all created equally. Some can detect multiple ranges from high to low voltage, while others can only detect one range.

Some are better for HVAC applications than others and some can measure the temperature of a surface. We hope that this article has provided helpful information that you can use to determine what non-contact voltage tester will be right for your next project. We’d love your feedback. Let us know if this article was helpful and if you have any questions!