Conductivity measuring device capable of compensating environmental change and measuring method

Abstract

The invention discloses a conductivity measuring device capable of compensating environmental change and a measuring method, the device comprises a conductivity sensor and a signal processing circuit,the conductivity sensor comprises a primary magnetic core, a secondary magnetic core and a liquid diversion pipe which are located in a sensor shell, a primary winding is wound on the primary magnetic core, a secondary winding is wound on the secondary magnetic core, the winding directions of the primary winding and the secondary winding are opposite; a liquid loop and a resistance loop are arranged between the primary magnetic core and the secondary magnetic core, a liquid resistor Rw exists on the liquid loop, wires of the resistance loop are respectively wound on the primary magnetic coreand the secondary magnetic core for one circle and are crossed at a gap between the two magnetic cores, and a loop resistor Rr and an analog switch S1 are connected in series in the resistance loop; and the signal processing circuit comprises an inverting amplifying circuit, an integrating circuit, a sampling holding circuit, an A / D module and an MCU which are connected in sequence. The device andthe method can compensate the measured value drift caused by external environment changes such as temperature and the like, and realize accurate measurement of the liquid conductivity.

Description

technical field [0001] The invention relates to the technical field of marine monitoring, in particular to a conductivity measuring device and a measuring method capable of compensating for environmental changes. Background technique [0002] Conductivity is a basic characteristic parameter of liquid, and conductivity sensors are widely used in industrial production and ocean monitoring. There are two types of conductivity measurement sensors commonly used at present: electrode type and inductive type. The latter is based on the principle of electromagnetic induction and consists of a primary coil, a secondary coil and a conductive liquid circuit. The primary coil winding is fed with an alternating current, and the generated circular alternating magnetic field generates an induced electromotive force in the secondary coil through the conductive liquid circuit. The induced electromotive force is measured, and the conductivity of the liquid can be obtained through calibration...

AI Technical Summary

Problems solved by technology

However, the magnetic core permeability of the coil is significantly affected by environmental factors such as temperature, which leads to changes in the coil inductance and induced electromotive force, which affects the measurement accuracy

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