FLUID ANALYZER WITH MODULATION FOR LIQUIDS AND GASES

摘要

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

主权项

1. A fluid analyzer, comprising:
an optical source and an optical detector defining a beam path of an optical beam; a fluid flow cell disposed on the beam path defining an interrogation region in a fluid channel in the fluid flow cell in which the optical beam interacts with a fluid; one or more flow-control devices configured to conduct an analyte fluid and a reference fluid stream through the fluid channel and the interrogation region, the flow-control devices being configured to manipulate the flow of a respective fluid in response to a fluid modulation signal to move a fluid boundary across the interrogation region, the fluid boundary separating the analyte and reference fluids when flowing together through the fluid channel; and a controller operative (1) to generate the fluid modulation signal having a time-varying characteristic to cause the fluid boundary to be moved across the interrogation region accordingly, (2) to sample an output signal from the optical detector at one interval of the fluid modulation signal during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, thereby generating corresponding output signal samples, and (3) to determine from the output signal samples a measurement value indicative of an optically measured characteristic of the analyte fluid.