Nitrite sensor

Abstract

The invention provides a nitrite sensor which comprises electrode connection wires, an electrode mounting disk, a reference electrode, an auxiliary electrode, a working electrode, a common-mode rejection electrode, an electrode excitation circuit, a control circuit, an electrode signal protection circuit and an electrode signal processing circuit, wherein the common-mode rejection electrode is additionally arranged in the sensor, so that a common-mode signal is generated; the electrode signal processing circuit is used for culling the common-mode signal to obtain a differential-mode signal generated by oxidization of nitrite; the differential-mode signal is amplified to acquire a voltage signal on a required level; finally, the amplified voltage signal is filtered and output. The nitrite sensor provided by the invention can be used for measuring nitrite and physically compensating changes of temperature and conductivity of a solution to be detected and interference of other ions in the solution on the sensor without software calculation, so that the measurement precision and stability are improved, and continuous on-line measurement on the concentration of nitrite in water can be carried out.

Description

technical field

[0001] The invention belongs to the technical field of sensor measurement, in particular to a nitrite sensor. Background technique

[0002] Nitrite is a general term for a class of inorganic compounds that widely exist in various water bodies and pickled products in nature and industrial production, such as groundwater, surface water, aquaculture ponds, drinking water, seawater, industrial wastewater, sausages, pickles Wait. It is often used as a food additive in industrial production to improve food taste, color and extend its shelf life. Nitrite is a toxic substance that is harmful to the human body and aquatic organisms. The nitrite sensor is a sensor that measures the concentration of its aqueous solution. When a stable excitation signal is applied to the nitrite ion selective electrode, the nitrite will undergo an oxidation reaction on the surface of the electrode, and the oxidation reaction will release electrons, and the electrode will collect these...

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