Answer / ashraf

A transducer converts energy from one form to another
form.Thermocouple (itself) converts heat energy into
electrical energy. But RTD needs an external source to give
electrical output.so, RTD could not be considered as a
transducer.

Answer / kamal.sh95

because tc change the temp in mv.and rtd incess the
resistance not change any form of enrgy

Answer / g_nagaraju2

Transducer means converts one form of enrgy into another
form.

thermcocouple converts temp into mV
RTD also converts temp into ohms.

in transducers we can classify active and passive
transducers.

Active trasnducers means no external supply
Ex:Thermocouple

Passive trasducers means with external supply
Ex;RTD

Answer / ulaganathan

in GENERAL CONSIDER AN THERMOCOUPLE WHENEVER IM
GIVING HEAT(PHYSICAL PARAMETER) THERE EXIST GENERATION
OF POTENTIAL RESISTANCE(ELECTRICAL PARAMETER) BY
SEEBECK EFFECT.IT IS AN SECONDARY IT IS AN SECONDARY
ONE

BUT INCASE OF AN RTD FOR THE CHANGE IN PHYSICAL
PARAMETER THAT IS HEAT IS CONVERTED TO CHANGE IN
DISPLACEMENT OF COIL (AGAIN AN PHYSICAL PARAMETER
MEASURESED. HENCE ITS AN SENSOR.IT IS AN PRIMARY ONE

Answer / amit

According to the instrument society of America-- " A Sensor or Transducer is a device which provides a usable output in response yo a specified measurand"
Here the o/p is defined as an electrical quantity and measurand is a physical quantity .but there is a small difference between them.... Sensor is an element that senses a variation in input energy to produce a variation in another same form of energy. Whereas , transducer usage transduction principle to convert a specified measurand into usable output.
ex.... A properly cut Piezoelectric crystal can be called a sensor and it becomes a transducer with appropriate electrodes and input/output mechanism attached to it.

Read more: http://wiki.answers.com/Q/What_is_the_difference_between_sensors_and_transducers#ixzz28RdhCpru

so RTD and TC both are transducers in industrial products form.

Answer / hardik patel

Just remember...

It is myth that output must be in electrical form for transducer. Just take an example of Bourdon Tube. It is considered at pressure transducer. Now there is no energy change between input and output. But output is convenient. So it is considered as Transducer.

If output of any device is in convenient form then it is transducer. Now between RTD and Thermocouple, mV is convenient so thermocouple is considered as transducer.

Answer / ulaganathan

y not in an rtd in which according to thermal
input it converts to an displacement i.e in material
expansion ,(may be in thin or wire wound type), so only
the output resistance is proportional to the change in
displacement of metals

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