Patent ID: 9360304
Filing Date: 2016-06-07
CPC Classification: G01B,G01D,G01F,G01V

Claim Text:
1. A method for measuring volumetric changes of an object, comprising: fixing an optical fiber to a reference member, the volumetric change of which is known, so as to follow deformation of the reference member when pressure is externally applied to the reference member; allowing test light to enter the optical fiber in a state of externally applying a known pressure to the reference member to which the optical fiber is fixed, and performing at least one of a reference Brillouin measurement for determining a reference Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a reference Raleigh measurement for determining a reference Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon; determining, from the result of the reference Brillouin measurement or the reference Rayleigh measurement, a Brillouin measurement coefficient or a Rayleigh measurement coefficient based on the relationship between the volumetric change and the frequency shift amount per unit pressure in each measurement; fixing an optical fiber to a sample member, the volumetric change of which is unknown, so as to follow deformation of the sample member when pressure is externally applied to the sample member; allowing test light to enter the optical fiber in a state of externally applying a known pressure to the sample member to which the optical fiber is fixed, and performing at least one of a sample Brillouin measurement for determining a sample Brillouin frequency shift amount based on the Brillouin scattering phenomenon, and a sample Rayleigh measurement for determining a sample Rayleigh frequency shift amount based on the Rayleigh scattering phenomenon; and determining the volumetric changes of the sample member from the sample Brillouin frequency shift amount or the sample Rayleigh frequency shift amount, and the Brillouin measurement coefficient or the Rayleigh measurement coefficient.