Conductivity sensor

摘要

A conductivity sensor is described in which electrodes are held in a desired position within a housing of the sensor by a number of slots accurately positioned within the housing. In one embodiment the slots are integrally formed within the housing. Once the electrodes have been inserted into the slots a thermoset resin is poured into the housing and cured. A through bore is then drilled through the housing, the electrodes and the cured resin to form a flow conduit through the sensor. A dual frequency excitation technique is also described that allows a measurement to be obtained of a polarisation resistance of the electrodes. In one embodiment this measurement is stored and used to correct subsequent conductivity measurements.

主权项

1. A method of manufacturing an apparatus for a conductivity sensor, the method comprising:
providing a mold or housing that defines a molding cavity providing a plurality of slots within said molding cavity; placing electrodes formed of a first conductive material in the slots to hold them partly within the molding cavity; providing a settable second material within the molding cavity before the second material has set, wherein the second material is different from the first material; setting the settable second material within the mold cavity; and after the electrodes and settable material have been placed within the mold or housing, forming a through bore that extends through said electrodes and said settable second material to define a flow conduit that passes through the mold or housing and along which fluid can flow; and wherein the slots are positioned within said molding cavity so that the electrodes are spaced apart along said flow conduit.