A three-electrode electrochemical dissolved oxygen sensor

Abstract

The invention relates to the field of dissolved oxygen content detection, in particular to a three-electrode electrochemical dissolved oxygen sensor. A cylindrical shell including a sensor, a replaceable oxygen-permeable membrane, a membrane cover, a gold electrode as a working electrode arranged in the cavity of the cylindrical shell, a silver electrode as an auxiliary electrode, a platinum electrode as a silver protective electrode, and the silver electrode The electrode, the gold electrode, and the platinum electrode are respectively connected to the polarization circuit through wires; the cavity of the cylindrical shell is filled with a liquid reaction electrolyte, and the electrolytic reaction solution includes the following components by weight: 74.55 parts by weight of potassium chloride , 0.561 parts by weight of potassium hydroxide and 1000 parts by weight of water. The electrochemical dissolved oxygen sensor of the present invention does not consume oxygen in the water sample during the measurement process, which improves the accuracy of detection. The auxiliary electrode adopts a double helix structure, which increases the contact area with the electrolyte and improves the response speed of the sensor. The sensor adopts The three-electrode system structure does not consume the electrolyte in the electrolyte and the silver of the auxiliary electrode, and the service life is greatly improved.

Description

technical field [0001] The invention relates to the field of dissolved oxygen content detection, in particular to a three-electrode electrochemical dissolved oxygen sensor. Background technique [0002] The concentration of dissolved oxygen in water is one of the important indicators to assess the degree of water pollution. In a liquid environment, if the concentration of dissolved oxygen is lower than 4mg / L, fish will suffocate and die due to lack of oxygen, while anaerobic bacteria can reproduce in large numbers, making the water stinky. In the field of wastewater treatment, the monitoring of dissolved oxygen concentration can improve the efficiency of degrading harmful organic substances in wastewater and reduce the operating cost of wastewater treatment plants. In the medical field, the dissolved oxygen concentration can reflect the ratio of hemoglobin binding sites occupied by oxygen molecules in the blood, so the dissolved oxygen solubility in the blood can be used fo...

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Problems solved by technology

[0003] The existing electrochemical dissolved oxygen electrodes have the following technical problems: (1) The oxygen in the water sample to be tested needs to be consumed during the detection process, resulting in inaccurate detection results; (2) The electrochemical reaction on the surface of the auxiliary electrode produces silver chloride The precipitation is attached to the surface of the electrode, and the accumulation of precipitation will affect the stability of the dissolved oxygen sensor; (3) The electrolyte needs to be replaced after a few months of use, which wastes a lot of labor costs; (4) The unreasonable design of the auxiliary electrode structure leads to the response speed of the sensor , poor accuracy and stability

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