An inductive sensor for measuring the position of a control rod within a nuclear reactor

摘要

A sensor 1 comprising a variable capacitor 2, an inductor 3, a voltage source 4 and a toroidal transformer 5 connected in series within an electrical circuit 6, which is tuned to be a resonant circuit. The sensor is used to measure the relative movement of the inductor 3 and a metallic member 9 by measuring changes in magnitude of the current in the resonant circuit 6 as the metallic member 9 enters the magnetic field 8 of the inductor 3. The sensor 1 can be used to measure linear and rotational movement. For example, the metallic member 9 may be attached to a control rod within a nuclear reactor, or the metallic member may comprise a rotatable disc (19, Fig 2) attached to the shaft of a pump within a nuclear reactor.