Patent ID: 7206376
Filing Date: 2007-04-17
Classification: G01N

Abstract:
1. Apparatus for measuring the density of a fluid, the apparatus comprising: means defining a flow path for the fluid; a gamma photon source; photon detector means positioned to receive photons from the gamma photon source via the fluid in said flow path; and means for determining the density of the fluid from a count rate of the photons received by the detector means; wherein the gamma photon source comprises a source which emits coincident photon pairs, the flow path comprises two relatively straight measurement portions extending in the direction of flow of the fluid and substantially aligned with each other each disposed to receive a respective photon of each pair, the gamma photon source is disposed between the adjacent ends of the two relatively straight measurement portions, the detector means comprises two detectors each arranged to receive photons which have passed along a respective measurement portion, and the density determining means determines the density of the fluid from the count rate of coincident photon pairs detected by the detectors.