Quasi-continuous leakage testing - supplying rapidly-diffusing reducing hydrogen gas to one side of component, and providing enclosed space contg. oxidising mixture at opposite side, and sensing reaction between gases using catalytic gas sensor

摘要

Quasi-continuous leakage testing of similar components or workpieces delivered quasi-continuously, e.g. on a conveyer belt, involves using a rapidly diffusing, reducing gas such as hydrogen as a test gas diluted with inert components. The mixture is delivered to the workpiece from one side without flowing past it. A small closed vol. on the other side of the workpiece (5) is filled with air or another gas mixture contg. an oxidising component. This mixture is enriched with a reducing component (4) so that a catalytic detector (2) in the vol. detects the reaction between the oxidising component and the reducing component diffusing in via the leak. ADVANTAGE - Quasi-continuous leakage testing of similar components or workpieces reduces testing time by using parallel testing. Avoids problems due to helium-leak detector using mass spectrometer, requiring no vacuum and enabling use of large number of gas sensors to be used by computer. Allows unambiguous relationship between sensor signal and workpiece.