US Patent 7521020 Device for precise chemical delivery and solution preparation

A burette (10, 110, 200) suitable for delivery of a reagent into a target solution (50) employs diffusion for delivering the reagent. The reagent is in the form of a solution, which is combined with a matrix material (22), such as a gel or porous ceramic. A membrane (32) covers a delivery outlet (20) to the burette. In one embodiment, the delivery outlet comprises a plurality of fine bores (36), each one filled with or covered by a membrane (38). Stirring of the burette or target solution is achieved with a stirring means (104, 106). A heating or cooling means (80) heats a tip (16) of the burette.