Patent ID: 9464979
Filing Date: 2016-10-11
CPC Classification: G01N

Claim Text:
1. Apparatus for monitoring a conductive fluid conduit arranged to carry a fluid stream, the apparatus comprising: a power supply having a reference mode of operation and a sample mode of operation, wherein in the reference mode of operation the power supply is operable to supply an alternating electric current through the fluid conduit at a high frequency such that the current is confined near the surface of the fluid conduit due to the skin effect, and wherein in the sample mode of operation the power supply is operable to supply an electric current through a full thickness of the fluid conduit; a plurality of electrical contact points connected to the fluid conduit; a voltage measurement device operable to measure the voltage between pairs of said electrical contact points so as to obtain reference values of electrical resistance of the fluid conduit when the power supply is in the reference mode of operation and so as to obtain sample values of electrical resistance of the fluid conduit when the power supply is in the sample mode of operation; and a processor operable to modify the sample values of electrical resistance based on the corresponding reference values of electrical resistance so as to compensate for temperature variations.