What is the Difference Between Transducers and Sensors?

A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument.

A transducer is a device, usually electrical, electronic, electro-mechanical, electromagnetic, photonic, or photovoltaic that converts one type of energy or physical attribute to another for various purposes including measurement or information transfer.

Transducers are machines used to change one type of energy into another. They can often be found as a component of more complex devices. Sensors are explicitly intended to measure and express levels of measurement. Quite often, sensors are composed of transducers; therefore, one can see how easy it can be to confuse the two.

Different sensors and transducers

Generally, transducers come in basic varieties of which there are almost endless applications. The first variety is contact transducers. This type is categorized by a single point of contact used to detect energy. There is generally a coupling material, such as water or oil, employed in order to prevent distortion between the source of energy and the point of detection.

Many sensors utilize contact transducers in order to detect energy levels and convert that into an electrical energy which would then influence a display meter. One type of contact transducer that was almost ubiquitous in the late 1980s and early 1990s were tape heads. These were found in any cassette player, touching the magnetic tape and reading the magnetic information that was on it. This information was then converted to an electric signal that was carried by wire to speakers or headphones and then converted back into sound waves.

The second most common type of transducers is the immersion type. These are intended to work in liquid environments. This type is effective at measuring sound, pressure, or other forms of mechanical energy. Paintbrush transducers are used like immersion types are, but they work in open environments and have highly sensitive crystals to detect even the faintest levels of energy. Antennae for radio waves are paintbrush types as they collect the broadcast radio waves and convert them into electrical energy that is converted back into sound by a radio’s speakers.

While transducers are specialized components used in machines to gather and convert types of energy, sensors are devices with a single purpose. Like transducers, they detect physical levels and many of them use transducers to do this, especially those that measure energy; but unlike transducers their purpose is exclusively to measure these levels and display that measurement in a form legible to people. Transducers are invaluable to this process because they can convert levels measured into basic forms of energy, like electrical, which can be displayed digitally or with an analog meter.

ALL TRANSDUCERS ARE SENSORS BUT ALL SENSORS ARE NOT TRANSDUCERS