How is the strength of a magnet tested?
How is the strength of a magnet tested? |
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The strength of a magnet is indicated by either its pull force or its magnetic field strength. A magnet’s strength is always stated in the product information for a magnet, however manufacturers use the following methods to discern this: | |||
Pull force |
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The pull force of a magnet is the amount of force required to pull a magnet away from the ferromagnetic material it is attached to. The pull force of a magnet is measured in either kilogrammes (kg) or newtons (N) by a pull force tester. | |||
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To use a pull force tester, a magnet is placed onto a thin steel sheet and the amount of force it takes to pull the magnet away from the steel is then measured. | |||
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The pull force of a magnet is determined by the strength of the magnetic force and not by its overall size. This means that a large magnet does not necessarily have a larger pull force compared with a small magnet. | |||
Magnetic field strength |
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The magnetic field strength of a magnet is measured in two units of measurement, discovered by Nikola Tesla and Carl Friedrich Gauss, called gauss and tesla. | |||
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Gauss and tesla both measure how dense the magnetic field is on the surface of a magnet. This is also known as a magnet’s ‘magnetic induction’.
To measure the magnetic field strength more accurately, the measurement ‘gauss’ is used. This is because 10,000 gauss are equal to one tesla. |
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The magnetic induction of a magnet is measured by a gauss-meter. A gauss meter works according to the hall effect, which is where electrical current flows through, and builds up to make itself equal to, a magnetic field. This build-up produces a readable voltage, which the gauss meter detects. | |||
