Patent ID: 6166806
Filing Date: 2000-12-26
Classification: A61B,G01F,G01P,G01S

Abstract:
A sensor for remote fluid flow measurements, said sensor comprising:a flexible tube having an optical opening formed in a sidewall thereof;first and second optical fibres disposed within said tube, said first and second optical fibres each having a longitudinal fibre axis and a terminal end disposed within said tube proximate said optical opening; anda single reflective surface disposed within said tube adjacent said terminal ends of said first and second optical fibres, said single reflective surface being separate from said terminal ends,wherein said optical opening and a portion of said tube surrounding said terminal ends of said first and second optical fibres and said reflective surface define a cavity, said cavity being filled with an optical cement forming an optical window,said single reflective surface being oriented such that light emitted from said terminal end of one of said first and second optical fibres is reflected by said single reflective surface in a direction having a component normal to the fibre axes through said optical cement into a measurement volume of the flow located outside and alongside said sensor, the reflected light being scattered within the measurement volume such that a portion of the scattered light that is within a field of view of the other of said first and second optical fibres is scattered back through said optical cement and is reflected by said single reflective surface into said terminal end of the other of said first and second optical fibres.