Sensor
In the broadest definition a sensor is a device, module or subsystem whose purpose is to detect events or changes in its environment and send the information to other electronic components, often a computer processor. A sensor is always used with other electronic devices, either as simple as a light or as complex as a computer.
The sensors are used in everyday objects such as elevator buttons sensitive to touch (touch sensor) and lamps that dim or illuminate touching the base, in addition to countless applications that most people never realize. With advances in micromachines and user-friendly microcontroller platforms, sensor applications have expanded beyond traditional fields of temperature, pressure or flow measurement, for example, in MARG sensors. In addition, analog sensors such as potentiometers and force-sensitive resistors are still widely used. Applications include manufacturing and machinery, aircraft and aerospace, automobiles, medicine, robotics and many other aspects of our daily lives.
The sensitivity of a sensor indicates how much the sensor output changes when the amount of input being measured changes. For example, if the mercury in a thermometer moves 1 cm when the temperature changes by 1 ° C, the sensitivity is 1 cm / ° C (it is basically the slope Dy / Dx assuming a linear characteristic). Some sensors can also affect what they measure; for example, a thermometer at room temperature inserted into a cup of hot liquid cools the liquid while the liquid heats the thermometer. The sensors are generally designed to have a small effect on what is measured; making the sensor smaller often improves this and may have other advantages. Technological progress allows more and more sensors to be manufactured on a microscopic scale as microsensors that use MEMS technology. In most cases, a microsensor achieves a significantly higher speed and sensitivity compared to macroscopic approaches.
Transducer
A transducer is a device that converts energy from one form to another. Normally, a transducer converts a signal into one form of energy in one signal into another. Transducers are often used within the limits of automation, measurement and control systems, where electrical signals are converted to other physical quantities (energy, force, torque), light, movement, position, etc.). The process of converting one form of energy to another is called transduction.
Transducers that convert physical quantities into mechanical ones are called mechanical transducers; Transducers that convert physical quantities into electrical ones are called electric transducers. Some examples are a thermocouple that changes the temperature differences in a small voltage or a linear variable differential transformer (LVDT) that is used to measure the displacement.