OPENING THE FLOODGATES
ON PARTIAL FLOW DILUTION
EPA ruling on PFD systems provides expanded opportunities for Sierra Intruments’
BG3 PM measurement system
With the recent EPA ruling that partial flow dilution (PFD) technology is now
legally recognized as an alternative
to traditional constant volume sampling (CVS) for particulate matter
(PM) measurement in engine exhaust
emissions, Sierra Instruments said its
BG3 PM measurement system is fully
compliant for PFD sampling for certification of engines tested on 2007 and
Tier 4 transient test cycles.
The BG3 PFD system is designed to
collect particulate samples over either
transient or steady-state test cycles in
any size engine, regardless of operating speed or stack size. It can be used
with any fuel (diesel, gasoline, natural
gas, etc.) and can be used in both
engine and chassis test cells.
Steady-state sampling times range
from two to five minutes depending
on the relative particulate emissions
output of the engine and the size of
the filter holder used, Sierra said. The
system can also be used as a diluter
for particle sizing instrumentation and
for gaseous emissions measurement
systems, while simultaneously and
accurately sampling particulate matter.
For the EPA partial flow dilution
regulation, the BG3 system satisfies
all requirements of 40 CFR 1065,
ISO 8178, ISO 16183, CFR Part
89, UN ECE regulation No. 49 and
Global Technical Regulation No. 4,
Sierra said. It can also add and control other emissions measurement
devices such as particle counters or
soot mass measurements.
The PFD technology was dem-
onstrated in testing with Sierra
Instruments’ BG3 PM measurement
system in a five-year cooperative
effort with the EPA, requiring the mea-
surement of PM over a two decade
range in concentration levels. In all,
120 pairs of simultaneously obtained
test data were taken at West Virginia
University and at Caterpillar Inc. in
Part 1065-compliant CVS-equipped
test cells.
Sierra Instruments’ BG3 PM measurement
system is fully compliant for partial flow
sampling for certification of engines tested
on 2007 and Tier 4 transient test cycles.
The device is designed to collect par-
ticulate samples over either transient or
steady-state test cycles in any size engine,
regardless of rpm or stack size.
values exhibit high rates of change
over very short time frames. Engine
inlet air mass flow rate can approach
