Patent ID: 7542143

Claim:
A flow cell for measuring a property of a pressurized flowing fluid using interrogating radiation at a predetermined wavelength, the flow cell comprising: a first and a second housing member, one of the housing members having a window transparent to interrogating radiation; a partition transparent to interrogating radiation mounted within the flow cell in spaced relationship to both the housing member having the window and to the other housing member, the partition having a first surface and a second surface thereon, the first surface of the partition confronting the window in the one housing member and the second surface of the partition confronting the other housing member, the partition being disposed such that the first surface of the partition and the window cooperate to define a cavity therebetween while the second surface of the partition and the other housing member cooperate to define a fluid sample chamber therebetween, the spaced relationship between the partition and the window being such that radiation reflected from a fluid in the sample chamber is able to undergo total internal reflection in the partition without evanescently coupling into the window; and an inflow and an outflow channel formed in the housing member having the window, the inflow and outflow channels each communicating with the cavity, the inflow and outflow channels being sized to pass a pressurized fluid through the cavity such that, in use, the spaced relationship between the partition and the window is maintained by a pressurized fluid in the cavity.