Magnetic fields are areas around a magnet where the force associated with the magnet’s pull is active. In order to determine the strength of a magnet, you measure the magnetic field. This provides information regarding how far away an object is before a magnet acts upon it and what sort of force a magnet can exert.
Units of Measurement
Fields are measured in units known as gauss. Other units that are used to discuss things like magnetic flux over an area include the maxwell and weber. One maxwell is the total flux across a single square centimeter sitting perpendicular to the field. To get an idea of how these measurements compare to real life examples, consider the magnet field of the earth. At the surface, that field measures about 1 gauss. A Neodymium, on the other hand, measures 10^4. Such a magnet would produce a force within its field that is 10,000 times stronger than the field of the earth!
Another important measurement when dealing with fields is the tesla. This is equal to one weber per square inch. The strongest known exert a force of 5 tesla.
What is Measured?
There are numerous units associated with a field because you are measuring for a number of different things. First, you measure the strength of a field. This tells you what the magnet is capable of. For example, a magnet used to create an office paperweight that attracts paperclips is not going to have a field with the same strength used in industrial manufacturing.
Measurements can also reveal the coercivity of a material. This provides information about what type of field would be needed to demagnetize a material. This can be important in industrial, technical and medical applications where materials may need to be counteracted for safety purposes.
Measurements can also determine the quality of the material in the magnet. This is how scientists and others can determine which materials make the best. There are numerous materials that exert some form of a field, but there are only some materials with enough quality to be used specifically for magnet-related purposes.
Measuring fields is important, because it allows users to determine whether or not a magnet is of the right strength and quality for the chosen task. For example, computer components like hard drives and monitors often contain to assist with data storage and electronic displays. However, magnets can be detrimental to certain types of outside storage devices. Therefore, computer manufacturers must be careful to choose material that will provide the right magnetic field for the job without impacting items and people outside of the hardware. This is the same in industrial, medical, and all other magnetic applications.