Sensors are used throughout engineering industries, from manufacturing assembly lines to chemical plants, helping to maintain a high standard regarding product quality and safety. In this article, we examine some of these sensors and how they benefit engineers and engineering processes.
Some sensors directly measure the volume of a liquid in a pipe (or a tank) of an engineering processing (or chemical) plant. These are known as ‘In-Line Fluid Sensors.’ Alternatively, there are also remote sensors situated outside of the pipe which can accurately measure the volume of a liquid.
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In-line fluid sensors are typically used with non-corrosive liquids where pipe damage is not an issue. On the other hand, sensors located outside of the pipes, such as ultrasonic sensors, can measure the volume of a liquid using waves. This minimizes the risk of corrosive fluids causing damage to some of the sensor’s sensitive components and enables the corrosive material to be measured efficiently.
In-line fluid sensors directly measure the volume of the liquid by measuring the internal wall of the vessel and the space occupied by the fluid. Sensors located outside of the pipeline require pulsed waves that bounce off the surface of the liquid and return to a transducer located within the sensor. These sensors then measure the time of flight between the wave generator and the receipt and this is then translated into the distance between the transducer and the liquid surface. The sensor then backs out a percentage of the measured span and outputs the volume in a readable format.
Measuring the flow outside of a pipe is slightly different. To measure the flow, solid particles are required to be in the fluidic flow. These particles reflect the incoming waves from the transducer within the sensor, and the motion of the particles changes the frequency of the incoming waves, which are then received by another transducer. The flow rate is linear to the frequency shift, and this value is then multiplied by the internal diameter of the pipe to give the volumetric flow within the pipe.
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Vision sensors are used to help maintain uniformity with products, to ensure product quality is high, and to check that certain operational efficiency is being achieved. These sensors can automate industrial processes and decisions, make measurements, and construe pass/fail decisions. They are used throughout various engineering-focused industries, from automotive to food and beverage, and can be used to determine the shape, size, shade, depth, and orientation of an object, alongside many other characteristics without any physical contact taking place.
Vision sensors use both image acquisition and image processing software to analyze any products that pass by it. The nature of vision sensors means that the inspection of multiple points on a passing object can be performed using a single sensor. Vision sensors can analyze in either color or black and white, and the analysis is performed using a data interchange from the video camera component to a computer processing unit.
A strain gauge (also written as a strain gage), is a sensor that uses electrical measurements to measure mechanical quantities. These sensors are widely used throughout civil and structural engineering disciplines to measure if a structure is under too much stress and strain from an external force. Strain gauges can be used to distinguish between tensile and compressive strain, so these sensors can tell if a material is undergoing compression or expansion.
The resistance of these sensors varies with the applied force. They convert force, pressure, tension, and weight into electrical measurements, and the change in resistance is then measurable. Special transducers can also be incorporated into these sensors to measure moments, pressures, accelerations, displacements, vibrations, and other properties.
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There are many types of strain gauge out there, and they all work slightly differently. However, regardless of the sensor used, the matrix and the adhesive must work together so that the strain can be transmitted. Three main factors determine which type of strain gauge is used, and these are the temperature, state of strain and the stability required.
There are also many more sensors used across engineering disciplines, and the sensor is a key component of many engineered products, processes or controls. However, the above examples show the breadth of sensors used across the engineering sector.
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