Mass spectrometer leak detection helium pre-filling method capable of prolonging detection waiting time of sealing device

A technology of waiting time for inspection and pre-filling with helium, which is applied in the direction of detecting the appearance of fluid at the leak point and using liquid/vacuum degree for liquid tightness measurement, which can solve the problem that large leaks cannot be identified by rough inspection methods.

Inactive Publication Date: 2013-07-17
NO 510 INST THE FIFTH RES INST OFCHINA AEROSPAE SCI & TECH
View PDF7 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0057] The purpose of the present invention is to overcome the defects of the existing mass spectrometry leak detection pre-filling helium method for sealing devices, and provide a mass spectrometry leak detection pre-filling helium method that can prolong the waiting time for sealing devices. The technical problem to be solved is that the sealing time can be extended The waiting time of the device, although it will lead to possible large leaks that cannot be identified by the rough inspection method, still maintains the dominant position of the pre-filled helium method, and the re-inspection of the pressure helium method plus rough inspection is used as a subsidiary of the pre-filled helium method. measures in order to maintain the advantages of the pre-filled helium method, that is, the minimum detectable equivalent standard leak rate is several orders of magnitude lower than that of the pressurized helium method

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Mass spectrometer leak detection helium pre-filling method capable of prolonging detection waiting time of sealing device
  • Mass spectrometer leak detection helium pre-filling method capable of prolonging detection waiting time of sealing device
  • Mass spectrometer leak detection helium pre-filling method capable of prolonging detection waiting time of sealing device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0242] Example 1 (see Figure 12 ): marked in the figure t 2i / V = 3 h / cm 3 or 30 h / cm 3 , L max = 1×10 -3 Pa×cm 3 / s, p i = 1.01×10 5 Pa. By formula (7) get t 2i, cp1 / V = 54.19 h / cm 3 ,so t 2i t 2i, cp1 , belonging to step S31 of "Content of the invention". As described in this step, the L max, H ≥ L 0 , L max ≤ L i, M . And when R i > R i, Lmax When , the leak rate is unqualified; and when R i ≤ R i, Lmax When the minimum detectable leak rate is less than L 0 The crude inspection method is used for leak detection of the tested device to confirm or exclude L H The existence of the leakage rate is judged to be unqualified or qualified. The statements in step S31 of "Summary of the Invention" are the same as those seen in the figure.

Embodiment 2

[0243] Example 2 (see Figure 13 ): marked in the figure t 2i / V = 100 h / cm 3 , L max = 1×10 -2 Pa×cm 3 / s, p i = 1.01×10 5 Pa. By formula (7) get t 2i, cp1 / V = 37.20 h / cm 3 , get from formula (8) t 2i, cp2 / V = 1046 h / cm 3 ,so t 2i, cp1 t 2i ≤ t 2i, cp2 . It can be seen from the figure R i > R i, Lmax , so it belongs to step S321 of "Content of the invention". As described in this step, the L max, H L 0 , L max ≤ L i, M , and when R i > R i, Lmax The hourly leak rate is unqualified. It can be seen from the figure L > L max , so the leakage rate is unqualified. Therefore, the statements in step S321 of "Summary of the Invention" are the same as those seen in the figure.

Embodiment 3

[0244] Example 3 (see Figure 14 ): marked in the figure V = 1cm 3 , L max = 1×10 -2 Pa×cm 3 / s, p i = 1.01×10 5 Pa, t 2i = 100 h; p e = 4×10 5 Pa, t 1 = 40min, t 2e = 60 min. By formula (7) get t 2i, cp1 = 37.20 h, obtained from formula (8) t 2i, cp2 = 1046 h, so t 2i, cp1 t 2i ≤ t 2i, cp2 . By formula (9) get t 2i, max = 8605 h, so t 2i t 2i, max . It can be seen from the figure R i R i, Lmax , R e > R e_Li, M , so it belongs to step S32221 of "Content of the invention". According to the description of this step, re-examination and rough inspection by helium pressure method should be used to judge whether R e ≤ R e_Li, M , from which it is judged whether L ≤ L i, M ,and t 2e cannot exceed the value expressed by equation (10) t 2e, max . like R e > R e_Li, M ,but L > L i, M , the leak rate is unqualified. And from formula (6) and formula (10) get t 2e, max = 2494 min, so fits t 2e Does not ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a mass spectrometer leak detection helium pre-filling method capable of prolonging the detection waiting time of a sealing device, is applicable to judging whether the leak rate index of a detected helium pre-filling sealing device is qualified, and belongs to the technical field of vacuum leak detection and instruments. The method has the advantages that the problem that a large leak hole in a molecular flow state cannot be identified by coarse detection due to long detection waiting time is solved, so that the dominant position of the helium pre-filling method is maintained; and by taking a redetection and coarse detection helium pressure method as auxiliary measures of the helium pre-filling method, the minimum detectable equivalent standard leak rate of the helium pre-filling method is lower than that of the helium pressure method by a plurality of orders of magnitude. The invention adopts the technical scheme that various types of judgment trend are analyzed and exhausted, corresponding methods are taken one by one, and corresponding criteria are made. The method is characterized in that the redetection and coarse detection helium pressure method which is taken as the auxiliary measures of the helium pre-filling method is endowed with a new important function, so that detectability is remarkably improved.

Description

technical field [0001] The invention relates to a pre-filled helium method for mass spectrometry leak detection of sealed devices, in particular to a pre-filled helium method for mass spectrometer leak detection that can prolong the waiting time of sealed devices, and belongs to the technical field of vacuum leak detection and instruments. Background technique [0002] American material testing standard "ASTM E 493-06. Standard Test Methods for Leaks Using the Mass Spectrometer Leak Detector in the Inside-Out Testing Mode (using the mass spectrometer leak detector for the leak rate inspection standard method of the internal gas escape mode) [ S]” pointed out that there are two kinds of leak detection method of sealed device helium mass spectrometry: partial pressure helium method (ie back pressure method) and pre-filled helium method. Refer to the People's Republic of China Aerospace Industry Standard "QJ 3212-2005. Helium Mass Spectrometer Back Pressure Leak Detection Metho...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): G01M3/20
Inventor 薛大同肖祥正王庚林
Owner NO 510 INST THE FIFTH RES INST OFCHINA AEROSPAE SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap