DOUBLE BEAM PHOTOMETER FOR MEASURING FLUID SAMPLES

摘要

A double beam photometric flow cell (12) for high pressure liquid chromatography having illuminated sample and reference passageways (26 and 28) therein, the sample passageway (26) receiving flowing fluid sample fractions for analysis. Regulating apertures (30 and 36) control the relative amount of light passed through the passageways (26 and 28) such that the light energy through the reference passageway (28) exceeds that through the sample passageway (26). This reduces the contribution of the reference path (28) to 'shot noise' in the photometer output signal.