Patent ID: 6904784

Claim:
A liquid chromatographic system including: at least one pumping system; a plurality of flow cells; a plurality of photodetectors; said pumping system supplying solvent to at least one flow cell of said plurality of flow cells; at least one light source; said at least one light source applying light to at least one of said plurality of photodetectors after the light has passed through a corresponding one of said flow cells; a time division multiplex circuit having a plurality of input means and a multiplex cycle time during which it multiplexes at least some of said plurality of input means for a time division whereby the time division multiplex circuit conducts signals from each individual input means of said some of said plurality of input means for a time division; at least one circuit means arranged to receive energy from at least one of said photodetectors for a substantial portion of said multiplex cycle time and apply it to a corresponding one of said plurality of multiplex circuit input means during said time division said at least one circuit means being a non-switching circuit with low bandwidth, whereby sensitivity is improved.