Determination of the thickness of a transparent plate using a reflective fiber optic displacement sensor

A fiber optic sensor for determining the thickness of a transparent plate (1–2.5 mm) is described based on a fiber optic displacement sensor. The sensor characteristics are found to vary with the change in the thickness of a plate. A theoretical model is proposed and validated with experimental results. The behavior of the sensor is evaluated and analyzed in terms of the numerical aperture and diameter of the fiber.