Knowing whether a magnet used in an industrial application actually delivers its promised power is critical. To prevent the frequent "low quality" issues encountered with imported magnets, accurately measuring the magnet's strength is mandatory. But how is this power tested?
1. Surface Magnetic Field (Measuring with a Gaussmeter)
Digital devices known as a Gaussmeter or Teslameter are used to measure the intensity of the magnetic field generated by the magnet. A probe is touched to the exact center of the magnet, and the reading is recorded in "Gauss" or "Tesla" units (1 Tesla = 10,000 Gauss). However, looking solely at the Gauss value does not definitively tell you how many kilograms that magnet can lift, because Gauss only indicates surface flux density independent of the magnet's total volume.
2. Pull Force Testing
For engineers, the truly critical metric is the Pull Force. This test is performed by attaching the magnet to a thick, smooth steel plate (usually low-carbon st37 steel) and forcefully pulling it away on a vertical axis using a mechanical hook or dynamometer. The exact Newton (N) or Kilogram (kg) value recorded at the moment the magnet breaks free from the steel surface determines its maximum pull force.
In safety-critical hardware like industrial Magnetic Lifters, the tested breakaway force is always divided by a safety margin of 3 or 3.5 to determine the Safe Working Load (SWL).