PC BASED SYSTEM FOR MAGNETIC PERMEABILITY MEASUREMENT

摘要

Measurement of magnetic parameters,, such as saturation magnetization (Ms), coercivity (Hc), susceptibility (x), permeability (μ), etc., which decide the application fields for magnetic materials is very important. Different methods are available to measure Ms. Hc, magnetic moment (n ) and X. However, the instrument, which gives initial permeability of magnetic materials directly, is rarely available. If geometry of the core, frequency and magnitude of applied magnetic field are held constant, then the mutually induced emf varies in proportion with permeability of core material. Using this principle, the system is developed to measure the initial permeability of magnetic material. The magnetic sensor is designed to pick-up magnetic character of the Sample Under Test (SUT). The precision analog to digital converter having 12 bit resolution is used for digitization of the signal. The PC is used for data acquisition and data processing for permeability. Employing this system the values of initial permeability for polycrystalline ferrites, Zn{sub}Mg{sub}(1-x)Fe{sub}(2-y)Nd{sub}yO{sub}4 (x = 0.0, 0.2, 0.4, 0.6, 0.8 & 1.0; y = 0.00, 0.05 & 1.00) are measured. These permeability values show close agreement with that of obtained from inductance measurement wherein Aplab make precision LCR meter is employed. The compositional dependence of the permeability follows the trend of saturation magnetization of the compositions.