STRAND DISCONNECTION DETECTING DEVICE FOR TRANSMISSION LINE

PURPOSE:To detect automatically and simultaneously disconnection of a strand on the whole periphery of a transmission line by using three slit beams of light. CONSTITUTION:Three slit beams of light whose directions are dislocated from each other are created, and among these three beams of light, one slit beam L1 is radiated directly to a transmission line 7 obliquely. The residual two slit beams L2 and L3 cover a part which cannot be covered with the slit beam L1 by radiating reflected light reflected by a reflecting mirror 40 to the transmission line 7 obliquely. In this way, an elliptic arc shape slit image 32 is formed to cover the whole periphery of the transmission line 7. These reflected beams of light are collected together, and are photographed by a single television camera 5, and an image is detected. A detecting image signal is introduced to a signal processing system 6, and information of an arc-shaped bright line is extracted from this image signal, and extracted bright line information and a predetermined standard value are compared with each other, and when a difference of not less than a prescribed value exists between both, it is judged that disconnection of an element wire exists, and this result is recorded. This inspection is carried out on an overall length of the transmission line.