PURPOSE: To provide an apparatus for determining the extent of deterioration of cable coating material while laying the cable as it is without requiring any destructive sampling.
CONSTITUTION: A probe P is applied to the outer peripheral surface of the coating material 12 of a cable 1 being laid and ultrasonic wave is transmitted from an ultrasonic transmitter S in the probe P toward the conductor 11 of the cable 1. The ultrasonic wave propagates through the coating material 12 and reflected on the inner face thereof before it is received by a receiver R. The propagation velocity of ultrasonic wave through the coating material is calculated at an operating section 2 based on the thickness of the coating material and the time required for the ultrasonic wave to be reflected on the conductor and received by the receiver R. The propagation speed thus calculated is then compared at a deciding section 3 with a speed preset for the coating under sound state thus estimating the extent of deterioration of the cable 1.
KURIBAYASHI TERUYUKI
TANNO SHOGO
OBARA HIDEO
