The Retrotec pressure pan can be used to locate duct leaks to the outdoors with a door fan. With the building pressurized to 50 Pa, the pressure pan can be placed over each register, to take a measurement of the pressure between the duct and the room where the register is located. The larger the pressure difference, the larger the leak(s) in the nearby ducts.

Pictured with pole which is not included. Pole can be purchased at one of the many different Home Improvement types of stores.