What is the difference between flux density and field strength? Which should a magnetic circuit designer be more concerned with and why?
Flux density is a measure of flux lines PER UNIT AREA. The unit for the value of flux lines per square centimeter is the Gauss, as read by a Gaussmeter. Field strength generally refers to the total flux available in the area of interest, and units are Maxwells or Webers; as when making a fluxmeter measurement using a search coil. A magnet will only generate a certain amount of flux, depending on its material, size and geometry. The magnetic circuit designer must utilize the available flux in the most efficient manner to achieve the desired results. That usually translates to producing some value of flux density in a defined area.
