9/18/24, 2:35 Sensors and
PM Transducers
Introduction to Sensors and Transducers. Definition
and Principle of Transduction
Definition of Sensors
A sensor or transducer is a device that gives a usable output (preferably, an electrical quantity) in
response to a specified measurand (physical quantity such as light, sound, temperature…etc)
Daily life examples of sensors include microphones, thermometer, accelerometers, infrared
sensors, speakers…etc
Sensor produces a usable output in response to a specified quantity. it uses the sensing principle,
that is it senses or detects a physical phenomenon.
A transducer converts one form of energy to another form. The process of conversion of energy
from one form to another is called transduction.
Not all sensors are transducers, but all transducers contain sensors. Sensing is the first stage of
transduction.
Principle of transduction
The input/output signals (in the form of energy) in a sensor can be divided into six. They are,
Mechanical
Thermal
Electrical
Magnetic
Radiant
Chemical
Some of the physical and chemical transduction principles can be grouped according to the form
of energy in which signals are received and generated.
about:blan 1/13
k
, 9/18/24, 2:35 Sensors and
PM Transducers
Mechanical input signal
Triggered by a mechanical force like stress or a push/pull
May cause change in temperature Friction effect, cooling effects) May
cause change in magnetic intensity Piezomagnetic effect)
May cause change in electricity (piezoelectric effect, resistive, capacitive and inductive
changes)
May cause change in radiant energy Photoelasticity, Doppler effect)
Thermal input signal
May cause change in mechanical energy Thermal expansion)
May cause change in electricity Seebeck effect, thermoresistance) May
cause change in radiant energy Thermo optical effects)
May cause change chemical reaction Thermal dissociation)
Electrical input signal
May cause change in mechanical energy Electrokinetic effects) May
cause change in temperature Peltier effect)
May cause change in electricity Charge controlled devices)
May cause change in magnetic intensity Biot-Savart’s electromagnetic law) May
cause change in radiant energy Kerr effect)
May cause change chemical reaction Electrolysis)
Magnetic input signal
May cause change in mechanical energy Magnetometers)
May cause change in temperature Magnothermal effects)
May cause change in electricity Galvanomagnetic effect) May
cause change in radiant energy Magneto-optical effect)
Radiant input signal
May cause change in mechanical energy Radiation Pressure) May
cause change in temperature Bolometer)
about:blan 2/13
k
PM Transducers
Introduction to Sensors and Transducers. Definition
and Principle of Transduction
Definition of Sensors
A sensor or transducer is a device that gives a usable output (preferably, an electrical quantity) in
response to a specified measurand (physical quantity such as light, sound, temperature…etc)
Daily life examples of sensors include microphones, thermometer, accelerometers, infrared
sensors, speakers…etc
Sensor produces a usable output in response to a specified quantity. it uses the sensing principle,
that is it senses or detects a physical phenomenon.
A transducer converts one form of energy to another form. The process of conversion of energy
from one form to another is called transduction.
Not all sensors are transducers, but all transducers contain sensors. Sensing is the first stage of
transduction.
Principle of transduction
The input/output signals (in the form of energy) in a sensor can be divided into six. They are,
Mechanical
Thermal
Electrical
Magnetic
Radiant
Chemical
Some of the physical and chemical transduction principles can be grouped according to the form
of energy in which signals are received and generated.
about:blan 1/13
k
, 9/18/24, 2:35 Sensors and
PM Transducers
Mechanical input signal
Triggered by a mechanical force like stress or a push/pull
May cause change in temperature Friction effect, cooling effects) May
cause change in magnetic intensity Piezomagnetic effect)
May cause change in electricity (piezoelectric effect, resistive, capacitive and inductive
changes)
May cause change in radiant energy Photoelasticity, Doppler effect)
Thermal input signal
May cause change in mechanical energy Thermal expansion)
May cause change in electricity Seebeck effect, thermoresistance) May
cause change in radiant energy Thermo optical effects)
May cause change chemical reaction Thermal dissociation)
Electrical input signal
May cause change in mechanical energy Electrokinetic effects) May
cause change in temperature Peltier effect)
May cause change in electricity Charge controlled devices)
May cause change in magnetic intensity Biot-Savart’s electromagnetic law) May
cause change in radiant energy Kerr effect)
May cause change chemical reaction Electrolysis)
Magnetic input signal
May cause change in mechanical energy Magnetometers)
May cause change in temperature Magnothermal effects)
May cause change in electricity Galvanomagnetic effect) May
cause change in radiant energy Magneto-optical effect)
Radiant input signal
May cause change in mechanical energy Radiation Pressure) May
cause change in temperature Bolometer)
about:blan 2/13
k
