What is a Voltage tester used for?

Voltage Tester is a testing instrument used for electrical power testing purposes. It is mainly used for detecting the presence of AC voltage in or around the object or surface and is very easy to operate. It can detect the presence of voltage in power cables, electric cords, lighting fixtures, circuit breakers, wires, power outlets, etc. These testers can indicate the voltage presence in the form of audio or visual signals. Few of them also use light or number to indicate the level of voltage present around the object or surface. The basic working principle of voltage tester is Capacitive Coupling, i.e. detecting the voltage without touching the wire or surface that is to be tested. A voltage tester is also known as a test light. The primary function of this tester is to protect the user from an accidental electric shock.

Working principle of voltage tester:

Basic principle – It measures the flux lines of the electric field formed between the earth’s potential and live component of the system.

Magnetic induction tester - It comprises a sensor winding the tip. This winding is then placed in the electromagnetic field. If the voltage is induced in the winding, then the light glows, or alarm is activated through the circuit.

Capacitive sensor element - It uses a capacitor coupling to detect both the electric field and energized conductors whether incomplete circuit or not. The user needs to touch the metal part of the tester to provide a ground reference. It allows the stray capacitance from the live conductor to flow towards the ground.

Types of voltage tester:

Non-contact voltage tester - It is also known as an inductance tester. It is one of the safest and easiest testers to use. Users can test the voltage in wires or devices without touching the surface or part of the device that is being tested. The reading is simply displayed on screen after taking the tip of the tester near to the wire. Both professionals and DIY homeowners can use it. It is suitable to be used near several places and objects like cables, cords, outlets, switchboards, junction box, circuit breakers, etc. Also, it is applicable for various sectors like security, communication, irrigation, entertainment and environment.

Neon voltage tester - It comes in a compact size with a neon light inside the device. It has two short wire leads with a metal probe on each end. It detects whether the voltage is present in the circuit or not. However, it cannot show the range of voltage present. For this user needs to touch the circuit wires with the wire probes.

Solenoid voltage tester - It is also known as a multi-function tester. It comes in both analog and digital models. It can test both voltage and polarity. Electricians mainly use it. It has two wires with a probe enlarged from bottom of the tester.

Digital Voltage Tester – It works in a digital and contactless way. It is a versatile tool suitable for multiple purposes. It’s primary function is to check if the technical instrument is working in the environment or there is a fault source present. It also detects interfered signals and overload issues. It is usually compact in size and light in weight. It has a setting option for phase detection and voltage measurement. The delivered signal can be in 2 forms – visual and acoustic.        

Pen-style voltage detectors - They have an LED tip that glows to indicate the voltage presence around the device to alarm the buzzer. They also come with an integrated torch option to use it even in the dark places. Some of its additional features include single-pole phase testing, continuity testing, and phase rotation testing.

Types based on AC/DC Voltage:

High-frequency AC Voltage Tester – It is also known as spark tester. It is usually mains powered and can detect electrical charges over 50,000 V. While operating blue brush discharge is observed around the electrode. This discharge changes into a single white spark when fault is identified.

Low-frequency AC Voltage Tester – It uses the transformer to step up the mains voltage to the required level. It can deliver the excess amount of voltage. The output of this detector is low-frequency AC voltage.

Pulsed DC Voltage Tester – It is lightweight and battery-powered. It works on the principle of the capacitor that is charged up to 400 V and discharged into a high voltage coil to produce a high voltage pulse for a shorter duration.

Continuous DC Voltage Tester – It is a portable and battery-powered device. It provides a lower-level output of fewer hundred volts up to 40,000 V. It works on the principle of the battery that triggers a high-frequency oscillator converting the battery voltage from 12V DC to high AC voltage.

Our best-selling voltage testers available online:

Precise - 90 to 1000 V AC Voltage Tester Volt Test Pen Detector - It is mostly preferred by electrician, linemen, electronic engineers, etc. It is applicable for power cables, circuit breakers, wall sockets, junction box, fuses, etc. It is very easy to maintain and clean the device. It is light in weight and has an operating temperature of -10 to 50 degree Celsius.

Precise - 90 to 1000 V AC Voltage Tester Volt Test Pen Detector

Fluke T+PRO - 1000 V Voltage Tester - It has a backlit LCD for easy usage. It can detect live voltage even with the dead batteries. It can detect both AC and DC voltage in the form of light, sound or vibration.

Fluke T+PRO - 1000 V Voltage Tester 

Kusam Meco 285HD - 22 KV High Voltage Detector- It is primarily used to detect the presence of an alteration field. It can be attached to the cable by a large metal clip that can be secured with cable tie. It senses the radiated magnetic field surrounding the cable and shows the live warning sign over the LED display.

Kusam Meco 285HD - 22 KV High Voltage Detector


Voltage detector is mainly used for certain electrical applications like battery voltage monitoring, maintaining the protection of the system, level discrimination, switching circuit in battery back-up, and microprocessor reset. So, start selecting the right choice of voltage detector for your electrical projects and make your space safer to work. To know more details of these voltage detectors you can visit our website.