Concept in Definition ABC

We call sensor yet device that automatically measures a variable, such as the temperature, the pressure or even the rate of rotation, among other things .

An interesting point to keep in mind is that Thanks to the information that a sensor gives us as a result, we can deduce other variables that are not precisely those that it is measuring. This example illustrates it: all the information that a flowmeter gives us (it is an instrument used to the measurement of the flow rate of a fluid or what is called mass flow) of hot wire is, in short, the electric power that is needed for a metallic thread to be kept at a certain constant temperature. With the information we receive we can deduce the mass of air that circulates around that same thread. This example is also applicable to many other sensor cases, as described for the equipment used for the determination of oxygen pressure in arterial blood; in the laboratory test popularly called "gases in blood ", two sensors detect oxygenation and carbon dioxide pressure, allowing indirect calculation of numerous associated parameters.

The sensors, basically, transform or reproduce a certain physical phenomenon (they can also be chemical or physicochemicals) in a "signal" that can be a unit of measurement (as in the case of thermometers or barometers), in sounds (such as systems safety by alarm) or in specific actions (for example, when we open the door of an ATM by entering a magnetic card). This process is known in the field of science as transduction, which constitutes the conversion of data into information in a different "language". Thus, a classic mercury thermometer is based on the expansion of the liquid metal in a column, which motivates its displacement along along a graduated ruler: the "data" arises from the dilation, the "information" is the temperature and the "transducer" is the column quantified.

Another well-known and commonly used example is the sensors used in alarm systems, which are installed in businesses or homes as a way to provide security to the property in cases of theft or assaults. Sensors movement Used in these cases, they allow detecting the entry or movement of a person in one or more areas of the home or business, once we have activated the alarm security system.

There are other devices with sensors that are used to notify people entering or leaving a property. In this case, they are small devices that are installed in doors, and when this is moved, they are activated producing a specific sound. These devices are always active, and there is no way to deactivate them when we do not want them to function (except to uninstall them from the place where they have been set). An analogous system is that used by elevators and forklifts, known in the jargon as "electronic eye", since it recognizes the presence of people at the door to prevent its automatic closing and thereby minimize the potential risk of accidents. The sensors weight in these elevators are a more sophisticated example, but with the same concrete utility.

To speak specifically about the automobiles we will say, for example, that the proximity sensor It is one that can detect people, cars or other objects. The most common sensors The proximity devices used are: ultrasound, near and far infrared, visible light camera, etc.

Although they are precisely called sensors because they "feel" or capture some condition that allows them to function for what they have been designed, a new branch of sensors are those of Wireless Network, that is, wireless connections (without the use of cables) for its activation and functioning. In this case, for example temperature or humidity can also be measured, but instead of using thermometers or barometers for this, It is about computerized sensors and connected to a computer network that allows you to transform their variations into signals electronic The initial technology for these sensors It was applied in space shuttles, but today it is part of various equipment used on a daily basis. Actually, modern touchscreens are an interesting example of sensors daily and dual, that is, they not only "sense" data for processing, but also "return" information. Consequently, the most current sensors are bi-directional utilities, since they can effect transduction in one direction or the other.

Finally, in biological sciences, we cannot forget that the sense organs act in turn as sensors, either unidirectional (vision, smell, hearing) or bidirectional, as occurs with the skin. Internal sensors that detect the spatial position of each organ and system provide the nervous system the information necessary for the preservation of the Balance, control of movement and interaction with the world around us.