High-stability film hydrogen sensor and use method thereof

Abstract

The invention relates to a high-stability film hydrogen sensor and a use method thereof. The film hydrogen sensor comprises a substrate, a hydrogen measurement unit arranged on the substrate for detecting hydrogen concentration, and a temperature control unit used for controlling the temperature of the hydrogen measurement unit, wherein the hydrogen measurement unit comprises a Wheatstone bridge structure, which is composed of a plurality of hydrogen sensitive resistance elements having the same electrochemical properties and is provided with 4 bridge arms, the number of the hydrogen sensitive resistance elements on the 4 bridge arms is the same, passivated composite coatings used for isolating hydrogen are arranged on the surfaces of the hydrogen sensitive resistance elements on 2 bridge arms among the 4 bridge arms, and the 2 bridge arms are 2 opposite bridge arms. According to the high-stability film hydrogen sensor provided by the invention, the hydrogen measurement unit based on the Wheatstone bridge structure is adopted, drift caused by inherent instability of the sensor and temperature drift can mutually counteract, the sensitivity is twice as high as that of a single hydrogen sensitive resistor, and the stability of the film hydrogen sensor is perfected significantly.

Description

technical field [0001] The invention belongs to the technical field of hydrogen sensors, in particular to a high-stability thin-film hydrogen sensor and its application method. Background technique [0002] Hydrogen is the main industrial raw material, and also the most important industrial gas and special gas. It is widely used in petrochemical, metallurgy, semiconductor and power industries. [0003] Compared with conventional gases, hydrogen has many unsafe properties. The explosion range of hydrogen in air is wider (4%-75% vol), the ignition energy is lower (0.019mJ), it is easier to leak, and the flame propagation speed is higher. Therefore, hydrogen leakage and explosion are one of the important causes of safety accidents. It is necessary to detect the concentration of hydrogen in the environment where hydrogen is used and monitor its leakage. [0004] The hydrogen sensor is a special sensor for hydrogen concentration measurement and hydrogen leakage monitoring. [...

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Problems solved by technology

[0008] 3) The sensor uses a single palladium-nickel alloy resistance sensor to realize the sensing of high-concentration hydrogen. Since the palladium-nickel alloy thin film has a large resistance temperature coefficient, in order to obtain high measurement accuracy, it is often only by improving the control of the sensor. Temperature accuracy is achieved, which is obviously not the best way

[0009] 4) The sensor uses a single palladium-nickel alloy resistance sensor to realize the sensing of a large concentration of hydrogen, but for a small concentration of hydrogen, the sensitivity of the palladium-nickel thin film resistance is small, which affects the measurement accuracy of the hydrogen sensor

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