we call sensor still device that automatically measures a variable, such as temperature, pressure or even speed, among other things .
An interesting point to note is that Thanks to the information that a sensor gives us as a result, other variables that are not precisely those that are being measured can be deduced.. This example illustrates it: all the information that a hot wire flowmeter (it is an instrument used to measure the flow of a fluid or what is called mass flow rate) gives us is, ultimately, the electrical energy that is needed to a metallic thread is 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 cases of sensors, as described for the equipment used to determine the oxygen pressure in arterial blood; In the laboratory test popularly called “blood gases”, two sensors detect oxygenation and carbon dioxide pressure, allowing indirect calculation of numerous associated parameters.
Sensors basically transform or reproduce a certain physical phenomenon (they can also be chemical or physicochemical) into a “signal” that can be a unit of measurement (as in the case of thermometers or barometers), into sounds (such as security systems 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 movement along a graduated rule: the “data” arises from the expansion, the “information” is the temperature and the ” transducer” is the quantized column.
Another well-known and daily use example are the sensors used in alarm systems, which are installed in businesses or homes as a way to provide property security in cases of robbery or assault. The movement sensors used in these cases, allow detecting the entry or movement of a person in one or more environments of the home or business, once we have activated the security system by alarm.
There are other devices with sensors that are used to notify the entry or exit of people to a property. In this case, they are small devices that are installed in doors, and that, when it is moved, are activated producing a specific sound. These widgets are always active, and there’s no way to disable them when we don’t want them to work (except uninstall them from where they’ve been attached). An analogous system is the one used by elevators and freight elevators, known in the jargon as “electronic eye”, since it recognizes the presence of people at the door to avoid its automatic closing and, with this, minimize the potential risk of accidents. The sensors of weight in these elevators are a more sophisticated example, but with the same concrete utility.
To talk 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 proximity used are: ultrasonic, 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 for, a new branch of sensors are those of Wireless Network, that is, wireless connections (without the use of cables) for its activation and operation. In this case, for example, temperature or humidity can also be measured, but instead of using thermometers or barometers for this, they are computerized sensors connected to a computer network that allows them to transform their variations into electronic signals. The initial technology for these sensors It was applied in the space shuttles, but today it is part of various equipment used on a daily basis. In fact, modern touch screens are an interesting example of everyday and dual sensors, that is, they not only “sense” data for processing, but they “return” information. Therefore, most current sensors are bi-directional utilities, since you can transduce in one direction or the other.
Finally, in biological sciences, we cannot forget that the sense organs act 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 with the necessary information to preserve balance, control movement, and interact with the world around us.
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