| 摘要 |
PURPOSE:To prevent the titled device from the influence of external noise by winding single mode optical fibers around the outer wall surfaces of respective thin and elastic sidewalls of high and low pressure rooms in a pressure receiving case, connecting a light source and a combining unit to the input terminals and output terminals of the optical fibers respectively and counting up interference stripes obtained by the combining unit. CONSTITUTION:The high and low pressure rooms 6, 7 having thin sidewalls 6a, 7a are formed in the approximately cylindrical elastic pressure receiving case 5, high pressure Pa and low pressure Pb and led into the rooms 6, 7 respectively through leading courses 8, 9 and valves 11, 12 are arranged in a connection course 10 between the rooms 6, 7 and the leading course 8. The single mode optical fibers 13, 14 are wound around the peripheries of the walls 6a, 7a and the input terminals and output terminals are connected to the laser light source 15 through a branching unit 16 and a detecting means 18 through the combining unit 17 respectively and a control circuit 23 connected to a counter 21 in the means 18 is connected to the valves 11, 12. Thus, the interference stripes generated on the basis of the differences of light length of the fibers 13, 14 which may be due to the differential pressure between the rooms 6, 7 are counted by the means 18 to detect the differential pressure. |
