Coordinated chromatography system.

摘要

A controller (30) based chromatography system (2) especially designed for flexibility of operation with ease of use and an icon based control panel (32), has a number of function panels (34), each having a function key (36), one or more indicator indicia (40) in the form of icons, letters or numbers, and associated indicator lights (38). A switching valve (4) is used to provide a mixture of two or more solvents (6, 8) to a peristaltic pump (12). The cyclic nature of the pump and mixer can create a resonant condition resulting in poor quality information from the UV monitor (20). The system minimizes this by the judicious selection of the total cycle time T for the switching valve. This can be done using a random number manipulated in a manner to come up with each time T. Alternatively, an irrational number is combined with the pulsation frequency of the pump to create each time T. A valve driver circuit (170) used with a valve (172) of the type which requires a higher voltage switching signal (174) and a lower voltage sustaining signal (176). The system permits the user to use three different nominal flow rate calibrations for peristaltic pumps using tubing having three different diameters (82, 84, 86). In addition to the precalibrated settings, the system can be user calibrated when desired. <IMAGE>