AGCIO Kappabridge Susceptibility Meter – This machine is the world’s most sensitive instrument for measuring rock samples bulk susceptibility, as well as the anisotropy of magnetic susceptibility (AMS), and the temperature dependence of susceptibility. The principle behind the machine - a sample is inserted into a sensing coil, which produces a net output voltage. The sensing coil is put in parallel with a zeroing coil, which is controlled by a ferrite chip. Thus, any sample input into the sensing coil produces an out-of-balance voltage that is proportional to the magnetic susceptibility of the sample. If measured in multiple directions the anisotropy of a sample can be determined, which allows a 3-D visualization of the internal fabric of the rock sample measured. If the temperature of the sample is changed during the susceptibility measurement, magnetic mineralogy can be determined (temp range of Kappabridge = -192 o to 700 o C).