EPA approves transient partial flow sampling system as alternative to CVS systems
EPA has approved Sierra Instruments, Inc. and Caterpillar, Inc. to use the Model BG-3 Transient Partial Flow Sampling System (TPFSS) as an alternate procedure in lieu of the full-flow Constant Volume Systems (CVS). After 30 years of using bulky, expensive, and maintenance-prone full-flow CVS systems to demonstrate engine compliance to exhaust particulate emissions regulations, engine manufacturers now have a more cost-effective and efficient tool to develop and certify cleaner engines. Caterpillar will save millions on a planned engine test cell expansions by standardizing on the Sierra BG-3 for both engine R&D and certification. Compared to CVS systems, the Sierra BG-3 is about 10 percent of the cost, is more reliable and versatile for engine developers, yields more meaningful engine emissions data, requires minimal maintenance, and is portable.