Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
127 words
Apparatus for detecting changes in chemical or physical parameters, which comprises a sensing optical fibre comprising a core surrounded by a sensitive cladding whose absorption spectrum varies with changes in the chemical or physical parameters when these are applied to the cladding, and transmissive optical fibre means, comprising a core surrounded by an insensitive cladding, for connecting at least one end of the sensitive optical fibre to a remote light source and a remote detector, the core of the sensing optical fibre having substantially the same diameter as the core of the transmissive fibre means and the refractive indices of both the sensitive and the in-sensitive claddings being less than the refractive indices of the cores of both the sensing fibre and the transmissive optical fibre means.
Claim 2
Dependent Claim
127 words
Apparatus for detecting changes in chemical or physical parameters, which comprises a sensing optical fibre comprising a core surrounded by a sensitive cladding whose absorption spectrum varies with changes in the chemical or physical parameters when these are applied to the cladding, and transmissive optical fibre means, comprising a core surrounded by an insensitive cladding, for connecting at least one end of the sensitive optical fibre to a remote light source and a remote detector, the core of the sensing optical fibre having substantially the same diameter as the core of the transmissive fibre means and the refractive indices of both the sensitive and the in-sensitive claddings being less than the refractive indices of the cores of both the sensing fibre and the transmissive optical fibre means.
Claim 3
Dependent Claim
58 words
Apparatus as claimed in claim 1, in the configuration of a probe having a reflective sensitive end, and a remote end connectable to both source and detector so that light fed into the remote end is transmitted to the sensitive end, and at least a portion is reflected back to the remote end for collection by the detector.
Claim 4
Dependent Claim
39 words
Apparatus as claimed in claim 2 wherein the core of the sensitive fibre is made reflective at one end and from the other end extends the transmissive optical fibre for conveying light both to and from the sensitive fibre.
Claim 5
Dependent Claim
89 words
Apparatus as claimed in claim 2 wherein the sensitive fibre has two ends each of which leads into a different transmissive fibre, the sensitive fibre being in the form of two portions lying adjacent each other and joined by a reflective coupling means whereby light launched from a source into the remote end of one transmissive fibre, travels through that fibre, through one portion of the sensitive fibre to be reflected into the other portion and thence along the other transmissive fibre for detection at the latter's remote end.
Claim 6
Dependent Claim
30 words
Apparatus as claimed in claim 1, comprising an optical fibre the ends of which are connectable to a light source and detector respectively, an intermediate portion having the sensitive cladding.
Claim 7
Dependent Claim
17 words
Apparatus as claimed in claim 5, wherein the intermediate portion is in the form of a coil.
Claim 8
Dependent Claim
36 words
Apparatus as claimed in claim 5 or claim 6 wherein the intermediate portion is located within a container for a fluid, and the end portions are connectable to a light source and detector outside the container.
Claim 9
Dependent Claim
27 words
Apparatus as claimed in any one of the preceding claims wherein the sensitive cladding for the sensing fibre comprises a chemochromic material embedded in a solid carrier.
Claim 10
Dependent Claim
30 words
Apparatus as claimed in claim 8 wherein the . chemochromic material comprises at least one pH sensitive dye and wherein the solid carrier comprises a water insoluble, water swellable material.
Claim 11
Dependent Claim
33 words
Apparatus as claimed in any one of claims 1 to 8 wherein the cladding comprises a material which can quantitatively undergo an irreversible colour change when subjected to the physical or chemical parameters.