METHOD AND APPARATUS FOR MEASURING MECHANICAL TEST VALUE FOR MATERIAL TO BE MEASURED

PURPOSE:To measure a mechanical test value in a non-destructive manner, by obtaining an increment magnetic permeability from magnetic characteristic of a measuring sensor arranged on a material to be measured. CONSTITUTION:An exciting coil is kept in contact with the face of a material 11 to be measured and a variable excitation power source is used to magnetize the material 11 being measured in the direction of the arrow (A). A measuring sensor 12 is arranged inside the exciting coil in contact with the material 11 being measured. A measuring excitation AC current flows through a measuring exciting coil 12a of the measuring sensor 12 to measure a signal (e) appearing at a measuring coil 12b. The value of the signal (e) becomes maximum at the points (4) and (7) of a hysteresis curve. Max. increment magnetic permeability is calculated from the max. value to determine a mechanical test value using correction constants such as components of the material being measured, finish temperature and dimensions. Thus, a mechanical test value can be obtained in a non-destructive manner.