BELL FLOW SYSTEMS
New low cost range of safe and hazardous area pressure transmitters
The AMO M10 is a new low cost industrial pressure transmitter
designed for general purpose pressure measurement. This sensor is rugged and
durable, providing accurate measurement even under harsh conditions,
available in gauge, absolute and sealed gauge versions. The MPM489 model is the ATEX approved version certified to ATEX
Exia IIC T4 Ga .
The Diaphragm is the sensing
element in these pressure sensors which is comprised of multiple layers
including a silicone substrate. The strain on which is determined using a
diffused resistor network. Monocrystalline silicone is the low-cost material
used in the manufacturing of these semiconductor based sensors. Silicone
material displays excellent piezoresistive properties.
When pressure is applied,
the diaphragm flexes and causes a deformation in its crystal lattice which ultimately
modifies the band structure placed on the diaphragm and changes the resistivity
of the material. Semiconductor resistors on the front side transduce this
tension into resistance changes by means of the piezoresistive effect.
Silicone in its crystal form is a
hookean material which, when flexed, has virtually zero hysteresis and hence
does not have any energy dissipation. Silicone is highly reliable as it displays
low fatigue stress characteristics and it can be deflected in the range of
billions to trillions of cycle without failure
Silicone has Young’s Modulus of
about 2*105 MPa, which is same as that of steel, but silicone is as light as
aluminium, with a mass density of about 2.3 g/cm3 . Silicone has a melting
point of about 1400°C.This high melting point makes silicon dimensionally
stable even at elevated temperatures. Its thermal expansion coefficient is
about 8 times smaller than that of steel, and is more than 10 times smaller
than that of aluminium. Silicone is an elastic material with no plastic or
creep below 800°C.These unique features makes it an ideal material for piezoresistive
pressure sensors
The method of assembly has a
substantial effect on the sensor's characteristic performance. These
piezoresistive silicone sensors convert mechanical tension to an electrical
signal and cannot distinguish between tension due to the signal (pressure) and
that caused by thermal expansion changes or other effects. The sensor data
therefore tends to have a thermal dependency which requires accurate on-board
compensation. The major advantage of this fabrication technique however
guarantees high precision and large volume production at low costs.
Both models are constructed from
stainless steel with a choice of grades to ensure application suitability.
Process connections and operating pressure ranges can be specified as can
options for signal output type, diaphragm material and electrical connections. Every
device is temperature compensated and calibrated and supplied with a traceable
serial number and calibration certificate. The electronics incorporate a
microprocessor based amplifier which means that there are no adjusting pots and
therefore the electronics are very stable, especially in high vibration and
high shock applications.
For further information contact mail@bellflowsystems.co.uk or call 01280 817304.
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Bell Flow Systems was established in 1997 with the emphasis being firmly
placed on the provision of flow measurement solutions to industry. Since
that time, Bell Flow Systems and its sister company Cortex Displays
Ltd have adapted and grown to meet new demands and challenges in an ever
changing market place. We now build systems, manufacture display
instrumentation and supply a range of products to the renewables market and the
environmental market.
Please contact us at pr@bellflowsystems.co.uk
with regards to PR or marketing@bellflowsystems.co.uk
with regards to marketing.