This is the device which is used to convert the force, pressure ,and load into the electrical signal. the major difference between the transducer and sensor is that ” sensor can only convert the physical quantity into the electrical energy or electrical signal.but transducer can convert any king of physical quantity into the desired energy like electrical , mechanical , etc.
so from this we can say that the every transducer is a sensor but every sensor is not a transducer.
WORKING OF PIEZOELECTRIC TRANSDUCER
piezoelectric transducer works on the principle of piezoelectric effect.when the piezoelectric material subjected to the pressure or force then due to the change in the dimension of the material the proportionate amount of voltage is generated.this effect is known as piezoelectric effect. so through the voltage we can easily measure the pressure or force applied on the material.
material of piezoelectric transducer are rochelle salts,lithium sulphate,dipotassium tartarate , quartz, ceramics amonium dihydrogen .
piezoelectric effect is direction sensitive. when the tensile force is applied on the piezoelectric material then the voltage of one polarity while compressive force produces a voltage of opposite polarity.so we can conclude that the magnitude and polarity of the induced surface charges are proportional to the magnitude and direction of the applied force.
1.piezoelectric transducer are the self generating transducer so they does not require any power supply.
2. they are light in weight.
3. easy to construct.
4. quartz type of transducer can be employed over a temperature range of -200 to 300 degree.
5. these transducer have very high frequency response.
1.their is the charge leaks off slowly through the leakage resistance of the transducer.
2.the output voltage is affected by the temperature variation of the crystal.
1.mainly employed to the high frequencey accelerometers
2. they are used to measure the force and pressure.
3.piezoelectric transducer can also be used to measured the temperature.
4.they are widely used in difficult applications such as internal combustion engine,fuel injection , ballistics ,blasts etc.