What Is A Clamp Meter And How To Use It?

A clamp meter, also known as the Tong Tester. It is an instrument used for measuring current without any connection to a circuit. You can use and operate and use this equipment conveniently to measure a live conductor without causing any damage or power loss to it.

In this article, you will get to know what a clamp meter is and how it works? You will also know what factors you need to consider while buying a clamp in the market.

First, let's find out what exactly a clamp meter is.

What with a clear digital display of results is a clamp meter?

A clamp meter is a device that is used for measuring current with convenience and safety. It efficiently measures current without using any test leads. To measure current with a clamp meter, you need to place a wire in the clamp meter's jaws. A magnetic field is formed when the current flows through the conductor. This device accurately detects the magnetic field to provide the corresponding current reading. Generally, the clamp meters perform just one job, i.e., measure current. However, many technicians use a combination clamp meter.

A clamp meter functions as per the magnetic induction principle to measure current without any contact. Like every conductor, the energy flowing through a wire also produces a magnetic field. The hall effect sensor of a clamp meter detects this magnetic field created by the current flow to generate less voltage throughout the sensor. It can be said that this sensor detects the magnetic fields produced by the low current flow.

Factors to consider when buying a clamp meter

Considering the importance of this tool, you should take no chances on its quality. Therefore, you must buy the best clamp meter that is available in the market. Below are some of the factors you need to consider to make a smart choice while buying a suitable clamp meter.

  • Safety

Safety is the most important factor that needs to be checked in a clamp meter. The entire function of a clamp meter is to prevent the physical contact between the conductor and the hands of the user. Therefore, you need to be sure that the clamp meter you choose has the highest ratings for safety.

  • Convenience

This factor includes the digital display of the results. You should check if the clamp meter you are buying has a proper display function or not. With a clear digital display of results, using a clamp meter on a live high voltage wire will be highly convenient.

  • Clamp Size

The clamp size is another key factor you need to consider. With a longer clamp size, it becomes convenient to measure longer conductors. Generally, the clamp sizes vary between 17 mm - 45 mm. You can easily select a suitable one as per your requirements.

4 Best Clamp Meters in India

Sl. No. 

Clamp Metre

Jaw Opening


MECO 1008 TRMS - 3 5/6 Digit 6000 Count LCD Auto-Ranging Digital Clamp Meter

30 mm


Kusam Meco KM 2719 - 3¾ Digits, AC TRMS Digital Clamp meter

28 mm


Metrix Plus 2250T - 1000 A Digital ACA Clamp Meter

52 mm


Fluke 303/EM ESP - 600 A AC Compact Clamp Meter

30 mm

MECO 1008 TRMS - 3 5/6 Digit 6000 Count LCD Auto-Ranging Digital Clamp Meter

Apart from measuring current in a live wire, these clamp meters are suitable for performing functions like data hold, audible continuity, and diode test. The MECO clamp meters require two AAA batteries to function up to 200 hours efficiently. In addition, these clamp meters come with a digital LCD with a total of 6000 display counts, and their resistance is nearly 600 ohm. Moreover, they have a 30 mm cable jaw opening with a CAT IV measuring category. Finally, they are supplied with essential accessories, including K type thermocouple, battery, pair of test leads, a carrying case, and an instruction manual.

Jaw Opening: 30 mm

Temperature: - 20°C ~ 1000°C / 0°F ~ 1832°F

Kusam Meco KM 2719 - 3¾ Digits, AC TRMS Digital Clamp meter

It is made with advanced technology, and it is suitable for measuring AC current upto 400 amperes. It comes with an AC voltage range of up to 600 V and a resolution of 1mV. Moreover, it has a K-type thermocouple temperature measurement function with a range up to 1000 degrees C. In addition to this, it also has a non-contact current detection function. This clamp meter comes with a digital LCD with a total of 6000 display counts.

Jaw Opening: 28 mm

Operating Temperature and Humidity: 0°C~30°C (?80%RH), 30°C~40°C (?75%RH), 40°C~50°C (?45%RH)

Metrix Plus 2250T - 1000 A Digital ACA Clamp Meter

It is a measuring instrument suitable for estimating electrical parameters. This clamp meter consists of different components such as a clamp, shift button, lever, inrush current button, LCD with proper backlight display, a dial, a hold, and input jacks. Moreover, it works on the principles of the transformers. The ACA Clamp Meter contains one copper-winding ferrite core that acts like a secondary winding, and the probes are connected for measuring purposes.

Jaw opening: 52 mm

Power: 1.5 V x 2 AA

Fluke 303/EM ESP - 600 A AC Compact Clamp Meter

Fluke 303/EM ESP is an efficient clamp meter that conveniently measures electric current. It is carefully designed and has a 30 mm jaw opening. Moreover, it can measure current up to 600 Amp. Fluke Compact Clamp Metre can measure the resistance and voltage with an accuracy of nearly +/- 5 digits. In addition to this, these clamp meters can efficiently measure current up to 400 A and voltage up to 600V. On the other hand, they also have a resistance of about 4000 ohms.

Jaw opening: 30 mm

AC Current Accuracy: 1.8 percentage +/- 5


A clamp meter is an essential and safe tool for measuring the current of a live wire. There are numerous options of this tool available in the market to choose from. Now that you know the function and features of a clamp meter, you can make a better choice to meet your needs.