A wide range of industrial applications requires the usage of pressure sensors. Continuous improvements in these sensors are necessary for new applications, including their use in more common applications like measuring fluid and steam pressure.
Recent power sensor technologies have made available devices with reduced size, better economics, more integration capabilities, and wider operating supply voltages, enabling OEMs to deploy sensors for applications like the Internet of Things. Additionally, with these sensors, it is possible to create products that are not only more sustainable but also feature additional embedded innovative features and less power consumption.
Along with a focus on applications, these sensors demonstrate a variety of methods and techniques for detecting pressure in industrial settings. Most notable among these are the MEMS or micro-electric-mechanical sensor technology.
Pressure is the force on a surface with a given surface area. Commonly, units for pressure measurement include the Bar, Pascal, and PSI or pounds per square inch. The sensor for a specific application typically defines the units it uses. For instance, it is customary to use bars or millibars to indicate pressure value in water-level applications. The automobile industry uses PSI to indicate pressure, such as in tires.
While measuring vertical distance or altitude, barometric air pressure is a common indicator. The reference here is the air pressure at sea level, which is equivalent to 1013.25 Mb or millibar. As the altitude changes, so do the air pressure.
In industrial applications, pressure sensors are generally of three types. These are the gauge pressure, absolute pressure, and differential pressure sensors.
A gauge pressure sensor uses the atmospheric or ambient pressure as its reference. This is typically 1013.25 Mb or 14.7 PSI at sea level. If the measurement is above ambient, it represents positive pressure, while a measurement below ambient is negative pressure. These sensors are useful in applications that require pressure measurement over longer periods, with little or no calibration.
Absolute pressure sensors use vacuum as the reference, with the absolute pressure of a full vacuum being zero PSI. Most absolute pressure sensors detect pressure below the atmospheric pressure. Altimeters are absolute pressure sensors using gauge pressure sensors.
Differential pressure sensors use a second pressure as a reference. This second pressure may be higher or lower than the pressure under measurement, or the atmospheric pressure. Differential pressure sensors are useful for measuring flow rates.
Industrial applications for pressure sensors have now evolved to the level where most sensors are smaller, smarter, and more conscious of energy consumption.
The various types of pressure sensors in use in the industrial environment, and the progress of MEMS technology, has enabled the semiconductor industry to make pressure sensors economical in high volumes.
With embedded compensation, low power consumption, and small size, these MEMS pressure sensors come in robust packaging. This allows wider use of MEMS sensors in industrial environments than was possible before. Most modern industrial systems now use a mixture of sensor technologies that not only run more efficiently but also waste much less energy. MEMS technology is the one leading in sensor applications in most industrial settings.
