What is Near Field Analysis (NFA) and how does it work ?
A. Magnetite concentrate and magnetite ore have proved to be difficult applications for the standard MoistScan® transmission technology. This is chiefly due to the magnetic nature or magnetic permeability of the product. The magnetic permeability is the degree of magnetization of a material in response to a magnetic field. Put simply, the microwave transmission signal is largely affected by the water within the Ore/Concentrate BUT unfortunately also affected by the magnetic permeability of the product. This is a problem because we cannot distinguish the moisture changes from the magnetic permeability changes. Recently Callidan has developed an analyser which will overcome these difficulties. We call it NFA (Near Field Analysis) but it is simply a direct measure of the magnetic susceptibility and microwave response (via reflection) of the material. It is called “Near Field Analysis” because the analysis zone will only penetrate the lower portion of the product upon the conveyor and NOT
