The ventilation measurement begins by uncapping the receiver. Because the rate at which the emitter releases gas is temperature-sensitive, the user needs to provide an average temperature estimate during the procedure for the test to be most accurate. At the end of the test period, the receiver is recapped and sent, along with the temperature readings and room volumes, to the Tracer Technology Center at Brookhaven National Laboratory for analysis, where an expert must analyze the results. The Tracer Technology Center sends the customer a computerized test report that includes the average air infiltration rate. Emitters are available with six different perfluorocarbon gases, making it possible to conduct simultaneous tests in six different areas or zones of a building.
Every zone measured requires one receiver.
Zones may be physically distinct areas, such as the basement, first and second floors of a house, or distinct heating zones in a zone-heated building. Utilizing more than one gas makes it possible to determine not only the air infiltration rate for each zone but also the airflow pattern between zones, such as between the basement and the first floor. This, in turn, makes it possible to determine air leakage into and out of each zone. The PFT technique can also determine the infiltration rates of other gases, such as radon. This is done by placing different emitters in the soil next to the foundation, below the basement floor, and in the house.