The Minneapolis Micro Leakage Meter (MLM) Measuring System has been developed by the manufacturer The Energy Conservatory in close cooperation with BlowerDoor GmbH in order to guarantee the functionality of ventilation systems by conducting airtightness tests of the duct system. With a measuring range of 0.17 to 78.5 m³/h, the MLM is also suitable for testing building components as well as small and highly airtight clean rooms.