Patent ID: 6465800
Filing Date: 2002-10-15
Classification: G01B,G01L

Abstract:
A differential transducer for measuring the curvature variations of a surface such as the surface of a diaphragm (5), characterized in that it comprises an assembly of two L-shaped optical elements (6, 7) whose first legs (8) are intended to be mounted on the surface in such a way that the outer faces of both second legs (9), which face each other and which are made from transparent material, extend substantially in parallel to each other and at a right angle away from said surface, an optical cavity (19) being defined there-between,a laser source (17) whose beam (16) is intended to be directed parallelly to said surface onto said assembly and perpendicularly to the outer faces of said second legs (9), and a photodetector (18) disposed to receive said beam after having passed through said cavity (19) and said optical elements (6, 7), each optical element being provided with three support tips (10, 11, 12) which are firmly applied against said surface and which are arranged at the corners of an equilateral triangle whose symmetry axis is parallel to the beam (16) axis, the support tip (10) on the symmetry axis being located close to the second leg (9).