MACEAS has designed the new helium leak tester for bipolar plates in a modular way. A system consists of at least one main module, which also includes a control cabinet and the operating elements. However, the system can be expanded as needed, and robot-assisted, fully automatic loading is also possible. Typically, two bipolar plates are inserted into the actual test chamber. Once the two bipolar plates are in the system, a mold closes around the two plates. This tool itself forms the vacuum chamber for the leak test to the outside. At the same time, it seals and valves allow the relevant channels of the plate to become vacuum chambers for the test themselves, one after the other. For cost reasons and to keep the helium background low, MACEAS does not work with pure helium gas here: the system itself produces a test gas mixture with 10 percent helium. However, in order to be able to test with such diluted test gas, the system must also be more sensitive by a factor of ten than when testing with pure helium. The smallest limiting leak rate against which the system can test the tightness of the bipolar plates today with INFICON's LDS3000 leak detector is at a helium leak rate of 1 ∙ 10-5 mbar∙l/s at 10 percent helium concentration.