Apparatus for the continuous measurement of the density of a liquid by utilization of the law of refraction

摘要

An apparatus for continuous measurement of the density of a liquid within prespecified limits, by utilization of the law of refraction, particularly for the continuous measurement of acid density of a storage battery of a motor vehicle for the purpose of determining the state of charge of the battery.PPThe apparatus is equipped with a photoconductive rod, a light source which radiates a pencil of parallel or nearly parallel rays into the rod toward a measuring surface, located at the end of the rod immersed in the liquid. The surface is struck by the pencil of rays at an angle with respect to the surface that equals at most the total reflection angle occurring at the lower limit of liquid density. A photosensitive element is located in the path of the ray pencil opposite a surface deflecting the pencil of rays, which is refracted by the measuring surface into the liquid.