The Importance of Sensors in Industry
In modern industrial sites, various sensors play a huge role. Manufacturers strive to adapt their products according to the ever-changing market demands by using alternative implementation options. Distance sensors (position, orientation, and presence sensors) are widely used in areas where it is necessary to determine the distance to objects or their presence. These devices are critically important tools in all productions where automation has been implemented.
Inductive Sensors
These sensors are designed solely for detecting metallic objects. Previously, they worked exclusively with iron and ferromagnetic materials, however, modern inductive sensors can also interact with non-ferrous metals. Another popular type of sensor in the industry is optical and photoelectric sensors, which, by their principle of operation, are quite simple, as they only need to absorb, reflect, or scatter light waves emitted by photo sensors. Today, the market offers self-learning photoelectric sensors that can adapt during operation.
Capacitive Sensors
This category of devices is responsible for measuring changes in the magnitude of the controlled object. However, their operating range is limited — only 80 mm. For measurements at greater distances, ultrasonic sensors are used. The principle of their operation is based on measuring the time it takes for ultrasonic waves to travel from the object to the sensor and back.
Electrical Flow Meters
Sensors in this group differ by their principle of operation and market segment:
- Coriolis: operate based on inertial forces affecting moving objects in the system;
- Thermal: the principle of operation is based on the transfer of heat from heaters to temperature-sensitive elements. Although their accuracy is quite low, they work effectively at low flow rates of liquids or gases;
- Turbine: function based on turbulence that occurs near submerged bodies in liquids.
By the nature of the measured pressure, these devices are divided into:
- Absolute pressure: the state in which the system is in a vacuum;
- Relative pressure: most commonly found in water supply systems.
Gas Sensors
Calorimetric sensors are designed to monitor the chemical composition of gas mixtures in areas where it is important to track the combustion process. They have a layer of oxide that converts concentrated gas into an electrical impulse. The popularity of such devices is due to their simplicity of use and low maintenance. The next type of gas sensor is infrared, which absorb infrared radiation from polyatomic gases. The gas analysis depends on the wavelength, and the accuracy of the obtained data exceeds average indicators. Among the drawbacks, one can note the high cost, although it decreases over time.
Temperature Sensors
These sensors are mainly used in metallurgy (steel-making furnaces), thermal power engineering (firing furnaces, heaters), and chemical industry (reactors). They are divided into non-contact and contact types. Contact sensors must directly contact the measuring objects and are represented by thermocouples and thermistors, which are affordable.