1. Elastic Pressure Transducers
Presented By: 2007-chem-20

2. Types of Pressure Measurements
Gauge pressure sensor
Absolute pressure sensor
Vacuum pressure sensor
Sealed pressure sensor
Differential pressure sensor

3. What are Transducers?
Transducers are the mechanical, electronic,
electrical, or electrochemical devices that convert
one form of energy to the property that cannot be
measured directly into the other form of energy
or property that can be measured easily. The
signal given to the transducer is called as input
this is the parameter that is to be measured but
cannot be measured directly. The signal obtained
from the transducer is called as output, which can
be measured easily.

4. Types of Pressure Transducers
1. Mechanical transducers
2. Electrical transducers
Note :
Elastic pressure transducers are mechanical
transducers.

5. Elastic Pressure Transducers
The elastic pressure transducers are
the mechanical elements that are used
for converting one form of energy
into the other form of energy that can
be measured easily.

6. Types of Elastic Pressure
Transducers
There are number of mechanical transducers,
some of the commonly used ones are described
below:
1) Bourdon tube pressure transducers
2) Diaphragm pressure transducers
3) Bellows pressure transducers

7. Bourdon tube Pressure Transducers

8. Advantages:
Low cost
Simple construction
Time-tested in applications
Availability in a wide variety of ranges,
including very high ranges
Adaptability to transducer designs for
electronic instruments
High accuracy, especially in relation to
cost

9. Disadvantages:
Low spring gradient (i.e. below 50 psig)
Susceptibility to shock and vibrations
Susceptibility to hysteresis

10. Diaphragm Pressure Transducers

11. Types of diaphragm pressure
transducers
Two types of diaphragm are generally
used:
1) Metallic diaphragm gauge
2) Slack diaphragm gauge

12. Metallica Diaphragm gauge

13. Slack Diaphragm gauge

14. Advantages:
Diaphragm Pressure Transducer cost is
moderate.
Diaphragm Pressure Transducer possesses
high over range characteristics.
Diaphragm Pressure Transducers are adaptable
to absolute and differential pressure
measurement.
Diaphragm Pressure Transducer has good
linearity.
Diaphragm Pressure Transducer is small in
size.

15. Disadvantages:
Diaphragm Pressure Transducer lack good
vibration and shock resistance
Diaphragm Pressure Transducers are difficult
to repair.
Diaphragm Pressure Transducer is limited to
relatively low pressures

16. Bellows Pressure Transducers

17. Advantages:
Moderate cost
Delivery of high force
Adaptability for absolute and
differential pressure
Good in the low to moderate
pressure range

18. Disadvantages:
Ambient temperature compensation needed
Unsuitable for high pressure
Limited availability of metals and work
hardening of some of them
Unsuitability of its zero and the stiffness
(therefore it is used in conjunction with (in
parallel with) a reliable spring of appreciably
higher stiffness for accurate characterization

19. References:
1. S k Singh “Industrial Instrumentation and Control”,
Tata McGraw HILL company Limited, New DEHLI,
1987
2. http;//vmpt.com/transducer.htm
3. http;//www.brighthub.com/engineering/mechanical/artic
les/41926.aspx
4. http;//www.omega.com/literature/transactions/volume3/
pressure.heml
5. http://en.wikipedia.org/wiki/Pressure_measurement