What is a sensor?
Watch the video
Surely you have often heard such a word as "sensor". Obviously, this word implies some kind of technical device. What is a sensor and how does it work? What types of sensors are there? Consider all these questions in more detail.
At present, it is customary to call a sensor an element that converts information received from a medium into an electrical signal in order to further transmit information to some other device. Usually the sensor is a structurally separate part of the measuring system.
Sensors are used everywhere: in cars, heating systems, water supply, at work, in medicine, even in catering establishments to measure the temperature in order to determine the degree of readiness of a dish.
There are several types of classification of sensors. We give the most basic.
By type of measurement:
- Pressure Sensors;
- Flow sensors;
- Level measurement sensors;
- Temperature measurement sensors;
- Concentration sensors;
- Radioactivity sensors;
- Displacement sensors;
- Angle position sensors;
- Mechanical measurement sensors;
- Vibration sensors.
- Element sensors;
- Integral sensors.
Classification according to the principle of action:
- Optical sensors that use electromagnetic radiation and react to water vapor, smoke and various types of aerosols. Refer to proximity sensors. The principle of their work is based on capturing by a sensitive sensor the effects of any stimulus, for example, water vapor. These sensors are widely used in automated control systems.
- Inductive sensors. They relate to proximity sensors, designed to calculate the position of the object. Inductive sensors perfectly capture the oscillations of the electromagnetic field. Their design is based on a generator, which creates an electromagnetic field, the impact of which on a metal object generates vibration amplitudes, to which the sensor reacts. Such sensors are widely used in metal detectors, as well as in various kinds of electronic locks.
- Capacitive sensors. It is these sensors that are used in cars as rain sensors, touch buttons of household appliances, and liquid measurement sensors. The principle of their action is to react to the action of a fluid. The insulator of such sensors has a dielectric constant. The fluid, acting on the insulator, causes the appearance of an electrical signal, which is converted into information. Such sensors are widely used in home appliances.
- Load cells. Strain gauges are devices for measuring force, pressure, torque, acceleration, or displacement. The mechanism of their action is based on the principle of elastic force. Such sensors are widely used in various types of scales. They convert the magnitude of the deformation into an electrical signal, in other words, the sensor detects the effect of any force on it, after which the elastic element is deformed and the resistance of the strain gauge that is built into such a sensor changes. Next, the information is converted into an electrical signal and transmitted to another device, for example, a display.
- Piezoelectric sensors. Such sensors are widely used in microphones and sonars. Their principle of operation is based on the polarization of the dielectric under the influence of mechanical stresses. In other words, piezoelectric sensors detect the change in the electric field, which was subjected to a mechanical effect. For example, in a microphone, this is voice exposure. The result of the deformation will be the conversion of the received signal into an electrical and transfer it to another device. These sensors received their birth thanks to Jacques and Pierre Curie in 1880.
- Magnetic electric sensors. These are sensors whose principle of action is based on the so-called Hall effect. These sensors are used in smartphones as the basis of the electronic compass, in electric motors, in current meters.
- Nano-sensors. Are in development. The most popular area for them should be medicine and robotics. It is assumed that these sensors will become a new class and will be widely used in the future.