A transducer is a device, usually electrical, electronic, electro-mechanical, electro-magnetic, photonic, or photovoltaic that converts one type of energy or physical attribute to another (generally electrical or mechanical) for various measurement purposes including measurement or information transfer.The term transducer is commonly used in two senses- the sensor used to detect a parameter as a form of energy and a translator which translates that form to an easily measurable form. Electrical transducers are defined as the transducers which convert one form of energy to electrical energy for measurement purpose. The quantities which cannot be measured directly like pressure, displacement, temperature, etc. Are required to be sensed and changed into electrical signal for easy measurement. Main objective of a transducer is to react only for the measurement under specified limits for which it is designed. A transducer should have the following basic requirements: LINEARITY Its input versus output characteristics should be linear and it should produce these characteristics in a balanced way. RUGGEDNESS It should be capable of withstanding overload and some safety arrangements must be provided with it for overload protection. REPEATABILITY It should be capable of reproducing the same output signal when the same input signal is applied again and again under unchanged environmental conditions, e.g., temperature, pressure, humidity, etc. HIGH RELIABILITY AND STABILITY The transducer should give minimum error in measurement for temperature variations, vibrations and other various changes in the surroundings. HIGH OUTPUT SIGNAL QUALITY The quality of output signal should be good, i.e., the ratio of signal to the noise should be high and amplitude of the output signal should be enough.