What is Gauss
The vocabulary in the world of magnets and neodymium magnet professionals can confuse the uninitiated. Especially when magnetic engineers and manufacturers of machines that use neodymium magnets are involved in the discussion. Several terminologies are specific to the neodymium magnet production and consumption industry, all describing one thing or another about neodymium magnets’ performance. Today, we will consider the term “gauss,” its origins, why it is essential, what it indicates, how to measure it, and what it does in a neodymium magnet.
What is Gauss?
Gauss, also known as the Gauss unit or the gauss, is the magnetic flux density or magnetic induction measurement in a neodymium magnet or a specific location. It is named after the German mathematician Johann Carl Friedrich Gauss, who developed the mathematical formula for measuring magnetic fields.
One unit of gauss is one line of flux in a 1 cm square surface area. It can also be in terms of flux density: 1 G = 1 tesla/meter2 = 10,000 nanoteslas/centimeter2. You cannot compare the gauss or magnetic flux density between two neodymium magnets unless they share the same geometry, i.e., the same size and shape. Also, the readings must be taken from the same location.
Several factors can alter a Gauss reading. Examples include temperature, time, location, nearby electronic devices, and other magnetic fields near the test site. For neodymium magnets that have been stored for future use, routine tests are essential to ensure optimal performance when it is time for their application, as age can affect the neodymium magnets’ strength and field.
Gauss is different from the magnetic pull or magnetizing strength and has a different function. Unlike most people believe, a higher pull power does not necessarily translate to a higher gauss.
For instance, if you have two neodymium magnets with equal pulls at their respective magnetic ends but different gauss levels, the one with the higher gauss will generate a stronger, thicker, and far-reaching magnetic field than the one with the lesser gauss. But both neodymium magnets will pull with the same force, possess the same holding power, and have the same max energy product (BHmax).
Gauss test is usually used to measure the distance or area of the field generated by a neodymium magnet. Still, a neodymium neodymium magnet may not be able to pull certain objects even within its magnetic field because pull strength reduces as the magnetic field thins out.
Hence, the PHMSA (Pipeline and Hazardous Material Safety Administration) rule says for transport by aircraft, any package with a magnetic field of more than 5.25 milligauss (0.00525 gausses) measured at 4.5 m (15 feet) from any surface of the box must be labeled magnetic. And the IATA (International Air Transport Association) rule says if the maximum field strength (gauss) measured at 7 feet is less than two milligauss (0.002 gausses), or there is no significant compass deflection. The package is not restricted to “Magnetized Material” in that case.
These rules imply that a magnetic field is magnetic at 5.25 milligauss since it can deflect a compass. But it is no longer magnetic at below two milligauss since it cannot deflect a compass, even though the magnetic field is present. To test the pull strength of a neodymium magnet, you should perform a strength test using a pull tester. But you will need a gaussmeter or tesla meter to measure the density or strength of the magnetic field.
What is Gauss Used for?
Gauss is used in many science and technology applications. Here are some of its uses.
Measures the Magnetic Field Strength
The formula for this is B = μ0M/(2πr), where M is the strength of the neodymium magnet, μ0 is a constant equal to 4π×10−7 T·m/A (the permeability of free space), and r is the radius of the neodymium magnet. Instead of using the formula, you can use standard lab equipment to measure a neodymium magnet’s field strength easily.
Electrical Systems
Gauss is commonly used in alternating current (AC). AC creates an electromagnetic field around its wires, which can be measured using a Gauss meter.
MRI Machines
Gauss distinguishes between different tissue types and other materials in an MRI machine.
Tissues have different electrical properties. It measures these properties and uses them to determine the kind of tissue present. For example, Gauss measures your brain tissue’s electrical properties if you have a brain tumor. It then detects any changes indicating the presence of cancerous cells.
Quantum Computing
Quantum computing uses Gauss for “superposition.” In this type of computing, information isn’t stored as bits (binary digits) but as qubits (quantum bits). These qubits can be in two states simultaneously: 0 or 1, or both 0 and 1.
They can perform calculations much faster than traditional computers. They don’t need all the bits to be on before working on them. They start working a bit at a time.
Why Do You Need to Know about Gauss?
Gauss is a measurement unit applicable in many areas; this means many people, not just physicists and mathematicians, need to know about it. If you are interested in neodymium magnets, the subject will interest you more.
The gauss has been used since its invention to measure potential magnetic fields. It is also helpful for measuring electromagnetic radiation and static electricity.
If you are going to use your neodymium magnet in an application that requires a high gauss, such as in sensors, you must know the gauss rating of the neodymium magnet to ensure proper performance. While several applications require a high gauss, they usually demand different gauss ratings. For example, an MRI machine’s gauss rating of the neodymium magnets is generally between 20,000 and 70,000. The high gauss allows them to create a powerful magnetic field for the scans they generate.
Importance of Gauss?
Gauss is important in different fields, including physics and engineering.
Magnetic fields are used in many different industries and scientific fields. The most common use of magnetic fields is in the production of electricity.
However, they are also used in medical imaging, particle physics, and many other areas.
How to Measure Gauss Strength?
You can easily measure Gauss strength using appropriate equipment. Here are some steps to follow when measuring them.
- Look up the gauss value for the neodymium magnet.
- Measure the distance from the neodymium magnet to where you want to measure the magnetic field strength.
- Measure the diameter and height of your solenoid, if applicable.
- Place your compass on a flat surface away from ferrous metal objects.
- Place your compass parallel to a bar neodymium magnet’s south pole pointing north, then read the value where the needle indicates.
- Place a clamp meter in series with an ammeter, and adjust it to measure AC milliamps or DC milliamps if you use a DC solenoid.
- Select your Hall effect probe and hook it up to a digital multimeter. Set it to measure micro-volts if you’re using an analog meter or micro-volts if you’re using a digital multimeter.
- Find out how many turns are on your solenoid windings and multiply by 10; this is N, in units of turns per meter (TPM).
Tesla VS Gauss
Magnetic induction is expressed in either Gauss or Tesla. The Gauss from the Centimetre Gram-Second (CGS) system corresponds to the Tesla of the International System of Units (SI).
The SI unit is multiples of ten, so one Tesla equals 10,000 Gauss.
The international system (SI) defines a gauss as being equal to 10−4 tesla (T), which means that if you have one Tesla within an area of one square meter, then there will be ten⁻⁴ gausses within that same area.
Some countries like the USA have refused to switch to SI units of measurement when it comes to magnetic flux density. Before familiarizing yourself with Tesla, it’s necessary to understand Gauss first to understand the subject better.
Conversion of Gauss and Tesla
The Gauss and Tesla are correspondences. They differ in these ways:
The three key differences between these two units are:
- Gauss is measured in units of current per length
Tesla is measured in units of flux density or magnetic induction
- Gauss is a unit of magnetism. It is named after the German physicist Carl Friedrich Gauss.
Tesla is also a unit of magnetism. It is named after Nikola Tesla, Serbian-American inventor, electrical engineer, mechanical engineer, and physicist.
- One unit of Gauss is equal to one Maxwell per square meter (1 m²).
One unit of Tesla is equal to one Maxwell per square centimeter (1 cm²
Conclusion
The unit of magnetic field strength is called Gauss. It is used in physics as a quantitative measure of the strength of magnetic fields. The unit is based on the SI unit (International System), which is a meter per second squared.
Gauss can be used to measure both permanent neodymium magnets and electromagnets.
Gauss is named after the mathematician who invented the Gauss electrometer. Engineers, scientists, and health professionals adopted the term.
However, the terminology has become muddled because there are two different systems. Some professionals use Tesla, while some use Gauss.
Nonetheless, Gauss remains an essential term in today’s neodymium magnet and magnetism industry.
