FLOAT OPERATED SIGNALLING DEVICE

摘要

The invention is concerned with a float operated signalling device of the kind in which a magnet follows the movement of a float in a liquid container and operates signal controls through a non magnetic wall. An open topped pan having a drain opening is attached to the magnet/float assembly and an auxiliary liquid supply is provided for depositing liquid into the pan at a rate greater than that at which it can drain out of the pan. When the pan contains liquid the float is dunked below the liquid in the container so that the magnet operates the signal controls for test purposes.