Sierra BG3 partial flow system a legal alternative to CVS

6 April 2011

Sierra Instruments announced that, as demonstrated in testing with Sierra’s BG®3, the US EPA has recognized partial flow dilution (PFD) technology as a legal alternative method to constant volume sampling (CVS) for 40 CFR part 1065 engine certification testing. The EPA direct final rule (DFR), published on November 8, 2010, became effective on January 7, 2011. Among other provisions, the rule allows the use of PFD systems for engine certification testing of PM emissions under transient conditions.

The BG3 PFD technology has been in use since 2003 for sampling exhaust PM emissions over both steady-state and transient test cycles in engine R&D applications.

The Docket for the DFR shows that the basis for the US EPA decision was the correlation to FTP and NRTC CVS transient test cycle PM, as required by 40 CFR Part 1065.12 and demonstrated by Sierra’s BG3. A nearly 5-year program in cooperation with the US EPA resulted in a BG3 vs CVS multiple engine, two-lab correlation study that included testing over US EPA 2007 and Tier 4 transient test cycles.

The Sierra BG3 is a widely used PFD technology and boasts an installed base of hundreds of units globally. Benefits of using the BG3, according to Sierra, include:

• Approximately 1/10^th of CVS system cost of ownership
• Approximately 1/100^th to 1/1000^th the annual energy usage versus a CVS, depending on CVS size and design
• Can be used on engines of any size and on any fuel in both engine and chassis test cells
• Patented partial flow dilution tunnel has ultra-low particulate losses and requires no cleaning for proper operation
• Integrity of internal flow systems and proprietary daily mirror calibration method yields excellent accuracy and repeatability of PM results over wide range of dilution ratios
• Easily portable from cell to cell to maximize flexibility and return on investment
• Satisfies all ISO 8178, ISO 16183, 40 CFR 1065 and CFR Part 89 requirements for PDF performance
• Ability to accurately measure PM either pre- and post-catalyst and/or DPF for research or deterioration factor (DF) testing

Source: Sierra Instruments