| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of measuring a reduction rate of a burning material, which allows the variation in waveform of a reflected echo to be surely made apparent even in the case of a low sound pressure intensity of a waveform of the reflected echo reflected by an inner hole surface of a solid propellant.SOLUTION: A transmission side probe 1 and a reception side probe 2 are arranged on an outer peripheral surface of a motor case 10, and an ultrasonic wave is transmitted from the transmission side probe 1 toward an inner hole surface 11b of a solid propellant 11 cylindrically loaded in the motor case 10, and a reflected echo P1 reflected by the inner hole surface 11b, an ultrasonic echo P3 propagated on the outer peripheral surface of the motor case, and a multipath reflection echo P2 resulting from multipath reflection in a motor case constituent material are received by the reception side probe 2, and respective propagation time differences of three echoes are obtained and are displayed on a B scope, whereby variation of the reflected echo P1 is made apparent. In this case, difference processing taking the i-th preceding reflected echo n-i as a reference with respect to a waveform n of the reflected echo P1 is executed, and difference data N obtained by this difference processing is subjected to amplification processing. |
