FEC manufactures a new type of leaking tester for HEPA filters that is self-developed and produced according to mist leaking test theory. The tester uses fuming particles between 0.3-0.5 um that are evenly arranged to meet the requirements for testing HEPA filter leakage. It can test a wide range of HEPA filter types, including those with and without separators, with high detection efficiency of only two seconds per filter. The device emits mist without harming operators or the environment during the detection process. It is currently the most cost-effective HEPA filter tester in the domestic market.