| 摘要 |
PURPOSE:To enable a highly accurate measurement of distance even under an adverse environment, by providing a reference reflector which reflects a part of incident ultrasonic pulse energy while allowed to transmit the other part thereof at a fixed position between a vibrator and an object to be measured to form a simple equipment with a better operability. CONSTITUTION:A probe head 11 of a distance measuring device 10 is provided with a nozzle 12 and a vibrator 13 which transmits or receives an ultrasonic wave. A reference reflector 15 which reflects a part of incident ultrasonic pulse energy while allowed to transmit the other part thereof at a fixed position between the vibrator 13 and an object 14 to be measured. The time interval t0 between the reflection pulse and an excitation pulse and the time interval t1 between the excitation pulse and the reflection pulse from the object 14 being measured are measured to calculate the current speed C of sound under water from the time interval t0 and the distance d0 between the vibrator 13 and the reference reflector 15. The time interval t1 is multiplied by the speed C of sound to compute the distance d1 between the vibrator 13 and the object 14 being measured. |
