Standard Test Methods for Leaks Using the Mass Spectrometer Leak Detector in the Detector Probe Mode
在探测器-探针模式下使用质谱仪检漏仪进行泄漏的标准试验方法
发布日期:
2006-12-01
1.1这些试验方法包括以4.5 x 10的速率测试和定位气体泄漏源的程序
13
摩尔/秒(1 x 10
8.
标准cm
3.
/s) 或更大。该测试可在任何装置或组件上进行,在该装置或组件上可产生氦或其他合适示踪气体的压差,且待测试泄漏的流出物侧可用于使用质谱仪取样探头进行探测。
1.2描述了两种试验方法:
1.2.1试验方法A-直接探测,以及
1.2.2试验方法B-累积。
本标准并非旨在解决与其使用相关的所有安全问题(如有)。本标准的用户有责任在使用前制定适当的安全和健康实践,并确定监管限制的适用性。
====意义和用途======
试验方法A经常用于测试可填充微量气体的大型系统和复杂管道装置。
通常使用氦。该测试方法用于定位泄漏,但除近似值外,不能用于量化。必须注意提供足够的通风,以防止试验现场的氦背景增加。结果受到氦背景和探头捕获的泄漏微量气体百分比的限制。
试验方法B用于通过在外壳内捕获泄漏气体来增加通过泄漏的痕量气体的浓度,直到可以检测到氦背景以上的信号。通过在记录的时间间隔内将校准泄漏引入同一体积,可以测量泄漏率。
1.1 These test methods cover procedures for testing and locating the sources of gas leaking at the rate of 4.5 x 10
13
mol/s (1 x 10
8
Std cm
3
/s) or greater. The test may be conducted on any device or component across which a pressure differential of helium or other suitable tracer gas may be created, and on which the effluent side of the leak to be tested is accessible for probing with the mass spectrometer sampling probe.
1.2 Two test methods are described:
1.2.1 Test Method A - Direct probing, and
1.2.2 Test Method B - Accumulation.
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
====== Significance And Use ======
Test Method A is frequently used to test large systems and complex piping installations that can be filled with a trace gas. Helium is normally used. The test method is used to locate leaks but cannot be used to quantify except for approximation. Care must be taken to provide sufficient ventilation to prevent increasing the helium background at the test site. Results are limited by the helium background and the percentage of the leaking trace gas captured by the probe.
Test Method B is used to increase the concentration of trace gas coming through the leak by capturing it within an enclosure until the signal above the helium background can be detected. By introducing a calibrated leak into the same volume for a recorded time interval, leak rates can be measured.