| 摘要 |
PURPOSE:To decrease the number of optical fibers employed for measurements of physical quantities, such as pressure, temperature, etc. and to simplify the construction of an apparatus, by using 2 different kinds of optical fiber, the coupling efficiency of the light between the optical fibers changing according to the propagating direction of light. CONSTITUTION:Light emission diodes 1, 4 are driven 7, 10 and generate beams of light 30, 32 of the same wave length respectively. This beam of light 30 is transmitted to a pressure sensor unit consisting of optical fibers 28, 29, diaphragm 22 etc. serving also as a reflecting board positioned opposedly on the detecting end of these optical fibers, after irradiation into the optical fiber 28 through a light divider 24. In this pressure sensor unit, amount of light corresponding to distances between optical fibers 28, 29 and the diaphragm 22 (pressure signal) is received by the fiber 29. This received light is converted to a received light voltage signal V31 after passing through light divider 25 and photoelectric converter 181. Similarly, a beam of light 32 from a diode 4 is divided 24 following the reversed path from the beam of light 30 to become a light-receiving voltage signal V33 after photoelectric conversion 171. A ratio V31/V33 of the signals V31, V33 is calculated by a calculating and processing circuit 35 and by the relation of the result and the specified pressure characteristics, pressure is determined by a computer 36. |
