Measurement of magnetic medium density using phasor method

A method of magnetic medium density measurement is described, which is very useful for the dense medium coal washing process. The inductive sensor structure and principle are discussed. The principle and realization of measurement system are also introduced. The exciting signal is sinusoidal wave current. The method can eliminates the temperature drift caused by the sensor resistance and increases the ability of anti interference. For increasing the sensor mechanical strength, the sensor structure is improved by putting the sensor in a stainless steel pipe. A slit to eliminate the eddy current in stainless steel pipe is cut. The linearity experiment and temperature experiment results are presented. The operation in coal preparation plant proves that the magnetic medium density measurement is stable and is able to meet the demand of the coal washing process.