Patent ID: 8324912
Filing Date: 2012-12-04
Classification: G01N

Abstract:
1. A measurement tool for measuring the dielectric constant of a fluid within a pipe, the pipe being electrically insulating, the tool having: a first capacitor plate mounted adjacent to a first part of the pipe, a second capacitor plate mounted adjacent to a second part of the pipe, an electrically conductive focusing plate mounted adjacent to a further part of the pipe, the further part of the pipe being located between the first part of the pipe and the second part of the pipe, the voltage upon the focusing plate being matched to that of the first capacitor plate, an electrically conductive screening plate mounted adjacent to and overlying the first capacitor plate, wherein the screening plate and the focusing plate are electrically coupled, the first and second capacitor plates, the focusing plate and the screening plate all being mounted to the outside of the pipe whereby they do not contact the fluid in use, a signal generator which can deliver an alternating electrical signal to the first capacitor plate, and a detector for measuring a signal dependent upon the electrical capacitance between the first and second capacitor plates.