Patent ID: 8246821

Claim:
Apparatus for performing liquid chromatography comprising: at least one solvent reservoir; a liquid chromatographic system including a microcontroller; a depth measuring instrument within said at least one solvent reservoir for generating a depth signal; said solvent depth measuring instrument being connected to the microcontroller whereby the microcontroller is configured for: 1) receiving the depth signal; 2) indicating when the depth of the solvent is low; 3) receiving and storing at least one parameter, the at least one parameter defining an amount of a solvent required from the at least one solvent reservoir for a corresponding chromatographic run; 4) determining a rate of change of the depth signal with respect to the at least one parameter; 5) directing a replenishment of the at least one solvent reservoir when the determining predicts a possible exhaustion of the solvent; and 6) terminating a chromatographic run when the determining predicts a possible exhaustion of the solvent.