Omega Products PX141-005V5V Installation Manual

PX140 Series

Pressure Transducers

INSTRUCTION

SHEET

M0258/1105

The OMEGA@PX140 Series
pressure transducers are solid state
piezoresistive devices ideally suited
to applications requiring exact
measurement of pressure where the
benefits of repeatability, low
hysteresis, and long term stability
are important. The PX140 series
offers state-of-the-art benefits of a
hybrid IC device, including
compactness, ruggedness and
reliability. Computer controlled
laser trimming provides close
control of important transducer
parameters at a lower total cost and
higher performance than can be
achieved with discrete circuitry.
Circuitry to provide temperature
compensation is an integral part of
the device and is optimized on each
unit as part of the calibration
procedure. Null and full scale
output are similarly controlled. No
adjustment or recalibration by the
user is required.

Three types of PX140 pressure
transducers are available to
measure positive pressures.
Differential and gage pressure types
measure pressure over five ranges
(0-1, 0-2, 0-5, 0-15, and 0-30 psi). For
vacuum measurement three
negative gage pressure ranges are
available (-1 to 0, -5 to 0, and -15 to
0 psi) Absolute types are available
in two ranges (0-15, 0-30, psi).

Two types are available to measure
both positive and negative
pressures. Differential and gage
types measure in four ranges ±1.0,
±2.5, ±5.0, ±15 psi).

PX140 pressure transducers

perform in industrial, consumer,
military, medical and automotive
environments. The heart of each
device is a 0.100" square silicon
sensor chip.

The sensing diaphragm with
implanted resistors is an integral
part of the chip. Pressure applied
on the diaphragm causes it to flex
and the resistance to change,
resulting in an output voltage
proportional to pressure. Because of
the unique construction, this output
is very predictable, providing an
ideal sensor element for OMEGA
pressure transducers.

The circuitry is contained in a
thermoplastic housing. The .010" x
.020" printed circuit board terminals
exit on opposite side from the ports.

SOLDERING

Limit soldering to 315°C (600°F)
maximum, with 10 seconds
maximum duration.

CLEANING

Select proper cleaning fluids, based
on contaminants to be removed.
OMEGA recommends alcohols or
fluorinated solvents.

WARNING!

READ BEFORE INSTALLATION

Fluid hammer and surges can destroy any pressure transducer and
must always be avoided. A pressure snubber should be installed to
eliminate the damaging hammer effects.

Fluid hammer occurs when a liquid flow is suddenly stopped, as with
quick closing solenoid valves. Surges occur when flow is suddenly
begun, as when a pump is turned on at full power or a valve is quickly
opened.

Liquid surges are particularly damaging to pressure transducers if the
pipe is originally empty. To avoid damaging surges, fluid lines should
remain full (if possible), pumps should be brought up to power slowly,
and valves opened slowly. To avoid damage from both fluid hammer
and surges, a surge chamber should be installed, and a pressure
snubber should be installed on every transducer.

Symptoms of fluid hammer and surge’s damaging effects:

a) Pressure transducer exhibits an output at zero pressure (large zero

offset). If zero offset is less than 10% FS, user can usually re-zero
meter, install proper snubber and continue monitoring pressures.

b) Pressure transducer output remains constant regardless of pressure.

c) In severe cases, there will be no output.

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