Hydrogen sensor for leakage detection and preparation method of sensitive element of hydrogen sensor

Abstract

The invention relates to a hydrogen sensor for leakage detection and a preparation method of a sensitive element of the hydrogen sensor. The hydrogen sensor comprises a gas chamber, one end of the gas chamber is provided with a gas inlet and a measuring probe, the other end of the gas chamber is provided with a gas outlet and a heating probe, a sensitive element is arranged in the gas chamber and comprises a substrate, a measuring electrode and a heating electrode, the measuring electrode is connected with the measuring probe, and the heating electrode is connected with the heating probe. The heating electrode is covered with a shielding layer, and the measuring probe and the heating probe are further electrically connected with a signal circuit located outside the gas chamber. The preparation method of the sensitive element comprises the following steps: plating multi-walled carbon nanotube loaded palladium-gold core-shell particle powder on the front surface of a substrate by adopting a vacuum coating method, and forming a measuring electrode after nano photoetching; sputtering platinum powder on the back face of the substrate in a vacuum mode, and forming a heating electrode after nanometer photoetching; and forming a silicon nitride film as the shielding layer by adopting a pulse laser deposition method to cover the heating electrode. The hydrogen measuring sensitivity is high and reaches ppb level.

Description

technical field [0001] The invention relates to a hydrogen sensor, in particular to a hydrogen sensor used for leak detection and a preparation method of a sensitive element thereof. Background technique [0002] In the process of automated production, industrial leak detection has become an indispensable practical technology to ensure the sealing of devices and systems, and can be widely used in aerospace, electronics industry, power industry refrigeration industry and other fields. [0003] Traditional industrial leak detection methods include differential pressure method, water detection method, ultrasonic method and tracer gas method. The detection rate of the pressure difference method is low, and it needs to be placed for a certain period of time, which is equivalent to the detection sensitivity of the water detection method, and only 10 -1 Pa·m 3 / s. Ultrasonic method can detect up to 10 -2 Pa·m 3 / s or so minimum leak rate. The tracer gas method is the most sen...

AI Technical Summary

Problems solved by technology

The tracer gas used in the tracer gas method includes radioactive gas, halogen gas, helium and hydrogen. Among them, the helium gas leak detection method is the most sensitive leak detection method, but the cost of helium gas leak detection is relatively high, and helium gas is rare in my country. Resources have been restricted by imports for a long time, and helium mass spectrometer leak detectors need to be implemented with a vacuum system, resulting in limited application of high-precision leak detection technology in industrial leak detection

[0004] Hydrogen leak detection method is an emerging gas leak detection technology, and its gas detection cost is more reasonable, but at present, hydrogen gas detection cannot achieve the same sensitivity as helium gas, which makes hydrogen gas leak detection method unable to be carried out in micro-leakage and precision device applications

Images