Abstract: Method and apparatus for determining Young's Modulus of a specimen by measuring the speed at which stress waves, either P-waves or S-waves, propagate therein. An embodiment of the apparatus includes two fixtures which are removably affixed to opposite ends of the specimen. A hammer having an accelerometer affixed to its head is used to strike the first fixture to produce stress waves in the specimen. A timer starts counting in response to an output generated by the accelerometer when the hammer strikes the first fixture. A second accelerometer affixed to the second fixture detects the stress waves and generates an output which causes the timer to stop counting. Further circuitry extracts the measured time, calculates a dispersion time delay based on material and length, and subtracts the dispersion time delay and a predetermined constant, both dependent on the material in the specimen, from the measured time to form a corrected transit time.

Abstract: A torque sensor comprising a first shaft having a fore end portion which is constructed such that a displacement of torsion thereof occurs; a second shaft connected to the first shaft through the fore end portion; a plurality of first magnetic segments each having a N-pole as a fixed magnetic pole and second magnetic segments each having a S-pole as a fixed magnetic pole; a plurality of first magnetism pickup path members and second magnetism pickup path members corresponding in number to the N-pole of the first magnetic segments and the S-pole of the second magnetic segments, respectively; and a magnetism detecting element provided in the first shaft so that it does not contact with the first shaft and adapted for detecting change in magnetic flux passsing through the first and second magnetism pickup path members.