OPTICAL LEVEL SENSOR FOR WASH AID REMOVABLE CONTAINER

A liquid level sensing system provides a removable reservoir incorporating a reflective surface that can be interrogated by a stationary optical sensor in a receptacle receiving the removable reservoir. The optical sensor may detect the presence of the liquid within the reservoir without connection to the reservoir simplifying the process of making the reservoir removable while still allowing sensing of its contents. By aligning the optical axis with the insertion axis of the reservoir sensitive optical alignment problems are minimized.