| Sensors, Inc.,
presents its next generation flow meter, the
SEMTECH-EFM 2
for the analysis of exhaust flow from both compression and spark
ignition engines and vehicles - on the road or in the field, in-use,
real-time. The
SEMTECH-EFM 2
is a rugged, compact device which directly measures raw exhaust flow
from a vehicle’s tailpipe continuously while the vehicle is in
operation. Together with Sensors’ on-vehicle
SEMTECH-EFM 2
analytical systems, total mass emissions can be instantaneously
calculated. At the heart of the flow meter is a
pressure differential device which provides greater accuracy over a
wider dynamic range than traditional instruments based on similar
technology. This is achieved through the use of four differential
pressure transducers, each designated for different portions of the flow
range. Considerable overlap allows for redundant measurements over much
of the flow range, allowing a single instrument to measure instantaneous
exhaust flow from idle through maximum speed and load with overall
accuracy better than 3% and linearity better than 1%. Moreover, the
automatic zeroing feature in
SEMTECH-EFM 2
enables pressure transducers to alternately zero and measure flow. This
eliminates any drift from the sensors during the test, even with
changing environmental conditions.
SEMTECH-EFM 2
overcomes traditional challenges specific to gasoline and diesel
testing.
The system employs ultra-low differential pressure
sensors combined with a proprietary pneumatic dampening device and
digital processing techniques to measure very low flow rates as well as
pulsating exhaust flow. These conditions are common to gasoline engine
testing particularly during idling.
Diesel engine testing presents its own set of
challenges, including collection of particulate matter in the flow
transducer and measurement at elevated temperatures. An automatic back
purge feature eliminates the accumulation of particulate material in the
flow transducer without the need for disassembly.
SEMTECH-EFM 2
is capable of accurate measurements with sustained exhaust temperatures
over 500°C, while accounting for the thermal expansion of the flow tube.
Sensors offers a total of five
SEMTECH-EFM 2
sizes to meet most test cell and on-vehicle testing applications. |
