What is Gauss?
The Permanent Magnet Design and Application Handbook, by Lester Moskowitz provide the following definition:
Gauss: The cgs unit of magnetic induction.
For clarification let us proceed to the definition of magnetic induction.
Induction, magnetic (general): The flux per unit area measured at right angles to the direction of the flux.
If after reading the above definitions you feel that you don’t know much more than you did before reading them, you are not alone.
Gauss is the most misunderstood term in magnetic therapy, greatly misused by unscrupulous manufacturers who use manufacturer’s gauss rating to indicate the strength of their products, when in truth the strength of a magnet depends on:
a) Strength of material (manufacturer’s gauss rating)
b) Size and weight of the magnet
For example: The earth’s magnetic field is 0.5 Gauss and a refrigerator magnet is 10 Gauss.
Considering only these numbers one would think that a refrigerator magnet is more powerful than the earth. This of course is incorrect, the earth, due to its immense size is immeasurably more powerful.
Unfortunately there is no standard mathematical formula to calculate the strength of a particular magnet. Magnets used for bio-magnetic purposes are described as open-circuit magnets because they do not have supplemental ferromagnetic parts to provide a complete path for the magnetic energy. Any type of “bare� magnet falls into this category. This would include magnets used in mattresses, support items, jewelry, and encased blocks.
Generally, magnets used in magnet therapy products range from 300 to 3000 Gauss.
A gauss meter is an instrument which can be used to measure lines of magnetic flux at a specific point on a magnet, but that reading provides no information about the total energy of the magnet being tested or about how far the energy will project from its surface.
When describing their products in terms of gauss, most manufacturers are referring to the manufacturer’s gauss rating of the magnetic material. This number will be the same for any size magnet made from the same material and in no way reflects the strength of a particular magnet. Once again, it is not a measure of the total energy of the magnet.
Fig. 3 shows a ferrite ceramic magnet measuring 10 5/8" X 3 1/2" X 1". The manufacturer’s rating for this magnet is 3850 gauss (the same as the magnet in Fig. 2 above). The flux density on the large flat surface of the magnet measures 950 gauss at the end, 720 gauss on the sides and 465 gauss at the center. The magnetometer measures 2 gauss at a distance of approximately 20" from the surface of the magnet.
From the illustrations above it should be obvious that the "gauss" readings don’t really provide any useful information.
Although it has the highest numbers, the magnet in Fig. 1 is so small that the total energy is quite low and practically imperceptible at only a slight distance from its surface.
It is therefore abundantly clear that people who market their products on the basis of gauss are deceiving their customers. The customer is led to believe that he is being provided information about the product which he can use as a basis for comparison and for making an informed decision. In fact, this is not the case.
Explanation of Different Types of Magnets
The four most common types magnetic material used in magnet therapy products are:
a) FLEXIBLE MAGNETIC RUBBER
Most commonly used in shoe insoles.
Material Gauss Rating: 2500 Gauss. On the average products made with this type of material will measure 200 � 350 gauss on the surface, depending on the thickness of the material.
Most commonly used in body wraps, pads and cushions.
Material Gauss Rating: Grade 8 � 4000 Gauss. On the average ceramic magnets used in magnet therapy products will measure 800-1100 gauss on the surface depending on the size of the magnet.
Most commonly used in magnetic jewelry and individually on pain trigger or acupuncture points.
Material Gauss Rating: 12500 Gauss. A typical neodymium magnet used as above will measure 1000-3500 gauss on the surface depending on its size.
d) SAMARIUM COBALT
Most commonly used in good quality jewelry where rusting is to be avoided. A very expensive magnet, very brittle, therefore labor intensive.
Material Gauss Rating: 11,000 gauss. On the average a samarium cobalt magnet used in jewelry will measure 1000 � 2500 gauss depending on its size.
Every magnet has a north and a south pole. In bio-magnetic terms the side of the magnet attracted to the earth’s South Pole is designated as the North Pole of the magnet. The side of the magnet attracted to the earth’s North Pole is the South Pole of the magnet.
In North America reputable magnetic products are either North Pole or Bi-Polar. When a magnetic product is called North Pole it means that all the magnets in the product are placed so that the North Pole contacts the body. When a magnetic product is called Bipolar it means that the magnets are arranged so that both North and South Poles contact the body.
The polarities are said to have the following effect:
North Pole: Calming, relaxing effect
South Pole: Stimulating, activating effect