| 摘要 |
PURPOSE:To accurately measure the axial tension of a bolt and to dispense with the precise processing accuracy of the bolt by using the scattered wave from the crystal grain boundary of the bolt. CONSTITUTION:An ultrasonic axial tension measuring device is equipped with a pulser circuit 8 generating pulses for driving an ultrasonic sensor, the ultrasonic sensor 1 converting the pulses to ultrasonic waves to propagate them through an object to be measured and converting the ultrasonic waves reflected by the end surface of a bolt 6 to an electric signal to output the same and a microcomputer 13 measuring the axial tension acting on the bolt 6 on the basis of an output waveform. The microcomputer 13 calculates the shift of the scattered waveform from the crystal grain boundary of the bolt 6 when no axial tension acts on the bolt 6 and the scattered waveform from the crystal grain boundary of the bolt 6 when axial tension acts on the bolt 6 and measures the axial tension acting on the bolt 6 on the basis of the calculated shift. |
