What is a Gauss Meter?

The modern version of the Gauss Magnetometer is known as a Gauss Meter. A Gauss Meter can measure the direction and the intensity of small (relatively) magnetic fields. For larger magnetic fields, a Tesla Meter, is used, which is similar, but it measures in larger Tesla units. A Gauss Meter comprises a gauss probe/sensor, the meter and a cable connecting both. The Gauss Meter works on the basis of the Hall effect discovered in 1879 by Edwin Hall.

A pioneer in the study of magnetic fields, Carl Freiderich Gauss (1777-1855), is also considered by all to be one of the greatest mathematicians. One of the first devices that could be used for measuring the direction and strength of any magnetic field, was developed by him – the magnetometer. He also developed a system of units to measure magnetism, and to honour him for the same, the modern unit for magnetic induction or the magnetic flux density in the metric (CGS) system is known as GAUSS. The basic unit of magnetic flux in the SI measurement system is TESLA (so named after Nikola Tesla, the father of electricity) and 1 TESLA = 10000 GAUSS.

What is the Gauss Meter working principle? What is the Hall Effect?

Magnetic fields effect electric currents as electricity and magnetism are related. When a current is passed through a conductor which is placed right angles to a magnetic field, the magnetic field force will push the electrons to one side of the conductor. The dis-balanced concentration of the electrons creates a measurable voltage which is directly proportionate to the strength of the magnetic field and the current but inversely proportional to the charge density and the conductor thickness. This effect is known as the Hall Effect.

The mathematical formula is V = IB/nd where “V” is the Voltage created, “B” stands for strength of the magnetic field, “I” the current, “n” the charge density, “d” is thickness of the conductor and “e” stands for charge of a single electron.

How Does a Gauss Meter Work?

The most important part of the Gauss Meter, the Hall probe, is usually flat to make it the best to measure transverse magnetic fields. Some probes are axial or cylindrical and those are used to measure parallel fields to the probe, for eg., a magnetic field inside a solenoid (cylindrical coils of wire that become magnetic when an electric current runs through them).

Both types can be used for general purpose magnetic field measurements, but flat or transverse probes are essential for measuring magnetic fields in open spaces, including small gaps inside or within magnets, or for simple magnets or ferromagnetic objects. Probes are fragile, especially when they are meant to measure small magnetic fields, and they are reinforced with brass for protection from rugged environments.

The meter uses the probe to send a test current through the conductor and due to the Hall Effect, voltage is produced, which the meter then records. As the voltage fluctuates and is seldom static, the meter usually freezes the readings at a specified value and records them, along with the highest voltage value detected. Some Gauss Meters are also able to differentiate between AC and DC fields as they automatically calculate the RMS (root-mean-square) of AC fields.

How to use a Gauss Meter?

1. Power on the Gauss Meter and hold the probe – the probe has the sensor.
2. Hold the probe over the magnet – flat if it is a Hall probe.
3. Hold for some seconds for the highest rating to be measured.

The above is the most general way to use a Gauss Meter. Most magnets come with pre-measured ratings but researchers, electricians, educators, product designers and some others find a Gauss Meter useful while developing or working on projects.

Who Needs a Gauss Meter? Where can a Gauss Meter be used?

A Gauss Meter can be a useful device to measure the strength of magnetic fields and some can even measure the direction of the polarity. A simple voltage tester is also in fact a type of gauss meter, as it detects electricity flow due to the magnetic field produced. A Gauss Meter can be used to measure:

✔️ DC and AC (40~500Hz) magnetic field
✔️ N/S polarity of DC magnets
✔️ Residual magnetic field after processing of mechanical parts
✔️ Intensity of magnetic field in magnetic application products
✔️ Residual magnetic field generated from the stress after processing of stainless material
✔️ Magnetic force of magnetizable material
✔️ Natural magnetism of various steel products
✔️ Magnetic field of motors and other home appliances
✔️ Magnetic Field Intensity of Permanent Magnets
✔️ Detecting the magnetic field of leakage generated from superconductive magnets
✔️ To simultaneously measure the Temperature along with the magnetic intensity

Prolonged exposure to magnetic fields can be harmful to health (though the study is not yet established), and if you’re concerned about the same, a Gauss Meter can also come in handy to measure and regulate the magnetic field strengths of various equipment around your house. Gauss Meters are used to measure electromagnetic radiation in places where people are living or working and the figures are used to compare against safety standard limits set by various global directives or regulations.

Industrial usage of Gauss Meters includes exact and repeatable measurements of magnetism strength connected to technical usage of permanent magnets and any ferromagnetic components. Gauss Meters allow for non-destructive magnetic field measurement in cases of DC or AC Motors, loudspeakers, magnetic circuits or components such as relays, magnetic switches or coils, classification of magnets and even for residual or stray magnetic/leakage fields. They can also be used successfully to determine whether any static or dynamic electromagnetic fields are affecting the working of precise electronic devices at their installation location.

The Metravi GM-197 Gauss Meter is for both static and electromagnets, DC and AC (40-500Hz), determines N/S polarity of Static Magnets, can measure intensity of magnetic fields in both Gauss and Tesla.

It measures up to 0~3000mT(milli Tesla) / 0~30000G (Gauss) and has Relative / Peak Hold / Real-time Zero function. Also comes with Auto Range, Data Hold, MAX/MIN Hold, GO & NO-GO alarms and alarm value set up function and production testing. It comes with capacity for 200 manual records and 6000 auto data logging. The interval can be set up using a PC. USB interface is available to share data with PC and there is an application software with real-time function.