Technical Paper
Advancements in Exhaust Flow Measurement Technology
2003-03-03
2003-01-0780
With the recent acceptance of the Bag Mini-Diluter (BMD) for low-level exhaust emissions measurement, there is an increased interest in exhaust flow measurement technology throughout the industry. Accurate tailpipe exhaust flow measurements can be considered the most “difficult” aspect of Bag Mini-Diluter systems due to the heat, water content, and transient behavior of the samples. Acceptance by the EPA and ARB of the Bag Mini-Diluter sampling system was based on the design and performance of the Flow Technologies E-Flow system with UGF-5 ultrasonic electronics. A number of noteworthy advancements have been made to this exhaust meter since the Agency's acceptance, and there appears to be a number of new technologies entering the market. At this time, ultrasonic flow measurement is the most prevalent and robust technology, however, other alternatives are worthy of consideration.