Abstract: An electro-mechanical transducer is disclosed for measuring physical parameters such as vibration, acceleration or the angular orientation of an object to which it is attached. A closed container partially filled with a fluid, has a light source and light detector mounted in optical communication with the container's interior. The arrangement of the detector and light source is such that light from the source must pass at least once through the surface (i.e., air-fluid interface) of the fluid before being detected. A constant incident light intensity is provided within the chamber and the resultant transmitted light is measured by the detector and an associated meter circuit. As the container is vibrated, or the angular relationship of the surface of the liquid with respect to the detected light rays is varied, the light transmissive and refractive properties of the liquid surface are altered, thereby altering the output of the light detector.

Abstract: An electro-mechanical transducer is disclosed for measuring physical parameters such as vibration, acceleration or the angular orientation of an object to which it is attached. A closed container partially filled with a fluid, has a light source and light detector mounted in optical communication with the container's interior. The arrangement of the detector and light source is such that light from the source must pass at least once through the surface (i.e., air-fluid interface) of the fluid before being detected. A constant incident light intensity is provided within the chamber and the resultant transmitted light is measured by the detector and an associated meter circuit. As the container is vibrated, or the angular relationship of the surface of the liquid with respect to the detected light rays is varied, the light transmissive and refractive properties of the liquid surface are altered, thereby altering the output of the light detector.