FLOW CONTROL SYSTEM

摘要

Method and apparatus for providing liquid flow at a controlled rate less than 100 microliters/minute, and for varying the flow rate in a desired way. A liquid is driven through a conduit by pressure. The rate of flow of the liquid through the conduit is measured and compared to a desired value. The resulting information is then used to make any desirable changes in the driving pressure. In one embodiment, which is particularly suitable for a mixture of liquids to be supplied to a gradient liquid chromatography column, the rate of flow of each of two or more different liquids is controlled individually, and the liquids are then mixed together.