The most common types of sensors simply explained
Sensors are indispensable in the modern world. There are countless types of technical sensors, but not only the measuring technology, but also nature itself has produced an overwhelming number of sensors. We give you an overview of sensors in the world of animals, plants and in everyday life.
What is a sensor? - easily explained
Sensors ensure that we perceive our environment.
- Sensors record the extent or nature of a physical, chemical or abstract quantity x. Therefore, sensors are also referred to as "x-meters", "x-sensors", "x-detectors", "x-sensors" or "x-meters".
- In contrast to indicators that only show whether a substance is present or whether it reaches a threshold value, sensors also register the extent.
- Once the sensor has measured a substance, further elements of the measuring chain must amplify this information, analyze it and then convert it into a stimulus that humans can receive via a sensory organ.
- Sensory organs are nature's sensors. In humans, the eyes recognize a part of electromagnetic radiation as sensors, the ears pressure fluctuations, the skin pressure and temperature, as well as nose and olfactory pits certain molecules.
- Without sensory organs, humans could not perceive their environment. Plants, for example, also record mechanical stress caused by feelers and probably light by ozone.
- The scientific discipline that tries to convert physical parameters into psychological perceptual parameters is called psychophysics.
What are the most common sensors?
The most common sensors usually measure values that we also perceive with our sensory organs or that at least directly affect our environment.
- Thermometers and pressure sensors measure temperature and pressure - just like our skin.
- Photocells and photodios register light - like our eyes.
- Microphones record sound in the frequency range of our hearing and often beyond.
- Particulate matter knives and some gas sensors work like a nose. Researchers use them to create an "electronic nose".
- Like our equilibrium organ, gyrometers, rotary movements and spirit levels record the relative orientation to gravity.
- Accelerometers register accelerations, distance measuring distances and absolute encoders lengths or angles. Acceleration of limbs as well as the detection of their distances and orientations to each other takes over the sense of position.
- Thermometers, barometers and hygrometers measure temperature, air pressure and humidity and thus provide information about the weather.
- CO sensors measure the concentration of carbon monoxide in the air to warn people of the risk of suffocation.
Everyday sensors
In addition to the sensory organs, our everyday life is shaped by technical sensors.
- Your smartphone includes a sound sensor for telephony, a light sensor in the camera, a triaxial accelerometer and an electronic spirit level.
- Some smartphones also have additional light sensors, barometers, Hall sensors and a compass.
- The scales in your bathroom and kitchen are weight sensors.
- Your car contains at least a speedometer, a tachometer and, if you move with the times, a distance meter in your parking aid.
- For example, smoke detectors are often equipped with carbon monoxide, carbon dioxide, temperature and light sensors.
- Timekeepers such as watches or automated calendars are likely to have the greatest impact on your everyday life. Strictly speaking, they are not sensors. You just perform a regular action.
If your smartphone does not have such sensors, you can connect it to external sensors via Bluetooth. But be careful: sensors can also be tricky. Security researchers are said to have managed to eavesdrop on smartphone users via the internal gyroscopes.