| 摘要 |
<p>There is described an apparatus (100) for monitoring a conductive fluid conduit (109) arranged to carry a fluid stream. The apparatus comprises a power supply (121), a plurality of electrical contact points (153,157,159,155,163,161) connected to the fluid conduit (109), a voltage measurement device (123), and a processor (125). The power supply (12) has a reference mode of operation and a sample mode of operation. In the reference mode of operation the power supply (121) is operable to supply an alternating electric current (AC current) through the fluid conduit (109) at a high frequency such that the current is confined near the surface of the fluid conduit (109) due to the skin effect. In the sample mode of operation the power supply (121) is operable to supply an electric current through a full thickness of the fluid conduit (109). The voltage measurement device (123) is operable to measure the voltage between pairs of said electrical contact points (153,157,159,155,163,161) so as to obtain reference values of electrical resistance of the fluid conduit (109) when the power supply (121) is in the reference mode of operation and so as to obtain sample values of electrical resistance of the fluid conduit (109) when the power supply (121) is in the sample mode of operation. The processor (125) is 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. There is also described a corresponding method for monitoring a conductive fluid conduit (109) arranged to carry a fluid stream.</p> |
