METHOD AND APPARATUS FOR CONTROL OF MASS COMPOSITION OF MOBILE PHASE

摘要

Described are a method and an apparatus for delivering a fluid having a desired mass composition. According to the method, temperatures of the fluids to be mixed are sensed and the densities of the fluids at the sensed temperatures are determined. The volume of each fluid is determined so that a mixture of the fluids at the sensed temperatures has the desired mass composition. The determined volumes of the fluids are combined to create the mixture. In one option, combining the determined volumes includes metering flows of the fluids sequentially into a common fluid channel. Alternatively, combining the determined volumes includes controlling a flow rate of each of the fluids and directing the fluids into a common fluid channel.