Title:
OPTICAL FIBER TYPE PHYSICAL QUANTITY MEASURING INSTRUMENT
Document Type and Number:
Japanese Patent JPH05157637
Kind Code:
A
Abstract:
PURPOSE:To simplify the constitution of the title instrument and, at the same time, to reduce the light loss of the instrument so as to improve its measurement accuracy by providing an optical multiplexer/demultiplexer which alternately transmits the Stokes' light and anti-Stokes' light of Raman scattered light returning from an optical fiber. CONSTITUTION:When the optical filter 64c of an optical multiplexer/demultiplexer 54 is set on an optical path, only the anti-Stokes' light of Raman scattered light made incident to the multiplexer/demultiplexer 54 from a connecting section 12 is supplied to a photoreceptor 56 from a connecting section 52a due to the actions of optical filters 64a-64c. The light supplied to the photodetector 56 is further supplied to an averaging circuit 58 after photoelectric conversion. The circuit 58 supplies the intensity signal of the averaged anti-Stokes' light to an arithmetic circuit 60 and, at the same time, outputs a control (conversion) signal to the optical multiplexer/demultiplexer 54. Upon receiving the signal, the multiplexer/demultiplexer 54 switches the filter 64c to another filter 64d by operating an actuator 66 and measures the intensity of Stokes' light by performing similar operations. The circuit 60 calculates the temperature distribution in an object to be measured from the intensity of the Stokes' light and anti-Stakes' light.
Inventors:
OZAWA YASUO
ENDO SHIGEHIRO
YAMAMOTO SATORU
ENDO SHIGEHIRO
YAMAMOTO SATORU
Application Number:
JP34787091A
Publication Date:
June 25, 1993
Filing Date:
December 03, 1991
Export Citation:
Assignee:
TOKYO ELECTRIC POWER CO
HITACHI CABLE
HITACHI CABLE
International Classes:
G01J5/08; G01K3/00; G01K11/12; (IPC1-7): G01J5/08; G01K3/00; G01K11/12
Attorney, Agent or Firm:
Tadao Hirata (2 outside)