A transducer is a device that transforms one form of energy into another. Most transducers convert electrical waves into the mechanical vibrations, or vice versa. Phonograph pickup cartridges, microphones and loudspeakers are some types of transducers.
Types of transducers include –
• Thermocouple
• Strain gauge
• Pressure transducers
• Sonar transducers
Thermocouple
The thermocouple is a type of transducer that comprises of a pair of wires of different semi-conductors or conductors, soldered or welded at one end. They are used for temperature measurement. Thermocouple temperature sensors are convenient and have a low heat capacity.
Strain Gauge
These transducers are devices that are used for measuring the distortion or strain on the surface. Some strain gauges work by the alterations in electrical resistance of a wire that is connected to the surface. Other strain gauges work on the magnetic induction in two coils, one of which is attached to the surface. Changes in capacitance can also be used in a similar way.
Pressure Transducers
The pressure measurement is usually achieved by determining the deflection of an elastic tube or diaphragm (for instance, a Bourdon tube). Material properties required for such type of pressure transducers include tubes or diaphragms that are similar to the restoring springs used in high-mechanical-impedance displacement transducers. These pressure transducers can also be applied with semiconductor fabrication techniques.
Sonar Transducers
These transducers transmit and receive the sound waves in water. Sonar transducers are also known as ultrasonic transducers that detect and generate vibrations above the normal frequency range of human hearing. They are used to clean delicate instruments, to cut hard materials, to measure liquid levels in fuel tanks of space vehicles and to drill oil wells.
