Fiber-optic physical quantity measurement system

摘要

PROBLEM TO BE SOLVED: To prevent misjudgment even in case an optical fiber has severed or the light source goes in failure by providing possibility of judging the soundness of the system. ;SOLUTION: A sensor 2 whose optical loss changes in compliance with the change in the physical quantity, is connected between an optical fiber 1a for signal transmission and another 1b for signal reception of a sensor part A. Without passing the sensor, a fiber failure sensing optical fiber 12b and also an optical fiber 12a for sensing failure in a photo-pulse generator are connected at the farthest and the nearest position of the transmitting and receiving end. A light receiver 5 receives photo-pulses to be taken out through the optical fiber 1b upon passing the sensor 2 via the optical fiber 1a from a photo-pulse generator 4 provided in the measuring part B. A signal processing device 6 measures the physical quantity in the sensor 2 on the basis of the change in the photo-intensity of the received pulses, while a signal processing device 13 for judgement of the soundness of system judges failure in the optical fibers 1a and 1b or in the photo-pulse generator 4 from existence or not of received pulse which has passed the optical fiber 12a, 12b.;COPYRIGHT: (C)1997,JPO