Wenzhou University

Ruizi Liu

Jie Wang

Changkun Dong

A vacuum-helium-leak-detection method based on a carbon-nanotube-based field-emission sensor that includes a carbon-nanotube-based cathode having a Raman amorphous peak I/graphite peak Iratio greater than 1.0. The method involves: setting a field-emission current at an initial, small emission current, recording an average of values of the field-emission current in a time period t, forming a sensing characteristic curve of the sensor, and performing fitting on the sensing characteristic curve so as to obtain an index curve; converting pressure values of helium gas into vacuum leak rates; and packaging the cathode into a vacuum chamber in a system to be detected, performing testing when a helium stream in the system to be detected reaches balance, obtaining an average of current variations in the time period t during the testing, and comparing the average with the index curve so as to determine a vacuum leak rate of the system to be detected.

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Wenzhou, China

Ruizi Liu