SENSORS & CONTROLS
High-Temperature
Sensors For
Commercial Engines
BY ROBERTA PRANDI
Most of the engine develop- ments that have occurred in any market have had
at least one unifying factor — just
about all of them have required an
expanded application of sophisticated
sensing elements. Modern vehicles
— from passenger cars to heavy-duty
trucks — utilize an array of sensing
devices, measuring everything from
temperature to pressure to position.
BorgWarner Beru Systems (Beru)
is a specialist in sensing technology
with more than 30 years in the automotive segment. The company is a
well-known manufacturer of diesel
cold-start and ignition technology for
gasoline vehicles, together with electronics and sensor technology for
application in engines, powertrains
and exhaust systems.
Most recently, Beru has developed
a new high-temperature sensor (HTS)
that is targeted toward commercial
vehicles and off-highway machines
and equipment. Already in production
for passenger cars, the new HTS is
designed to withstand high exhaust
gas temperatures and can be used to
monitor and protect components such
as turbochargers, exhaust gas recirculation components, diesel particulate
filters and diesel oxidation catalysts
from excessively high heat loads.
Ing. Ulrich Schneider, sensors product manager at Beru in Ludwigsburg,
Germany, said the new HTS offers a
short response time together with more
long-term stability and a versatile structure. “Our aim was to develop a closed
sensor to meet our partners’ demands
for short response times,” he said.
For the sensor element of the HTS,
Beru uses a resistance temperature
device (RTD) made of platinum. “For
this type of measurement Beru has
opted for a thin-layer platinum shunt
resistor that offers an optimum combi-
nation of measurement range, signal
yield and stability,” said Schneider. “In
fact, the Beru HTS covers a measure-
ment range from - 40° to 1740°F and
ensures a standardized characteristic
line as per DIN IEC 751.”
Schneider said while conventional
platinum sensors consist of a plati-
num thin layer applied to an alumi-
num oxide substrate protected by a
thin layer of glass, for the new plati-
num shunt resistor Beru replaced this
layer with an insulating ceramic layer
applied densely by special processes.
This solution protects the sensor ele-
ment from chemical aging, he said.
With a tem-
perature meas-
urement range of
- 40° to 1740°F, the
new High Temperature
Sensor from Beru can be
used to monitor turbochargers
and aftertreatment components in
commercial diesel engines.
the risk that the tip will collect carbon
deposits with a negative effect on the
sensor’s response time.
“This type of clogging does not hap-
pen with closed designs. Furthermore
the dimensions and geometry of our
new HTS make it extremely flexible.
We can achieve immersion depths
from 25 to 70 mm (0.98 to 2.75 in.) and
bending angles from 90° to 180°.”
For the new HTS Beru has devel-
oped a separate test and inspection
procedure. A “hot shake” test consists
of mounting the sensors on a vibrat-
ing table, heating them to 1652°F for
144 hours. At the same time, they are
subjected to different types of vibra-
tions, such as those occurring within
the engine.
Another procedure involves an
alternating temperature test where
the sensors move onto a pneumatic
table 12,000 times inside a 1742°F
furnace, while outside the temperature reaches around 302°F.
HTS sensors are being manufactured
on two fully automated lines at Beru’s
headquarters in Ludwigsburg dp
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On This Company Go To
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at www.dieselprogress.com
