Hydrometer for use with car battery - has two interconnected chambers and bar magnet inside ring magnet for zero setting

摘要

An acid density measuring instrument for use in accumulators such as car batteries. It consists of a cylindrical chamber with a suction bellows at one end and an inlet nozzle for the electrolyte at the other. The instrument is also fitted with a float which is submerged in the electrolyte and is linked to the main body of the instrument via a lever. A pointer is held in the zero position of a scale by a magnet. The instrument has two chambers (1, 2) separated by a partition (7) with a link hole for the electrolyte. There is also a hole (11) in the side wall (7) to regulate the level (10) of the electrolyte in the side chamber (2). The spring system consists of a rod magnet within a ring shaped diametrically polarised magnet.