Pressure transducers are known by many names, including pressure transmitters and pressure sensor, but something they all have in common is that they measure the pressure of a liquid or a gas by converting the pressure into an analog signal.
These devices have a wide range of real-world applications, and there are actually many different types of pressure transducer for specific purposes. To gain an understanding of the different types available, first we must understand the types of pressure that can be measured.
Pressure is measured as either absolute, gauge or differential. Many measurements are taken relative to ambient air pressure but this is not the only kind; other measurements may need to be taken relative to a vacuum.
Absolute pressure
Absolute pressure is used in devices such as barometers and altimeters, and also has a range of applications in vacuum packing machines to ensure that a fixed vacuum is applied when sealing food.
It is taken in reference to a vacuum, and is gauge pressure plus atmospheric pressure. It is useful because locations change and the atmospheric conditions change as they do; for example, when you are at different elevations.
Gauge pressure
Gauge pressure has a wide variety of real-world uses – for example, it can be used to control tyre pressure in finding the correct pressure compared to atmospheric pressure, allowing the tyre to perform most effectively. It is also used in medicine as a part of suction devices that apply vacuum gauge pressure during surgery in order to remove fluids.
Gauge pressure measures pressure relative to the current ambient atmosphere, making it effectively the opposite of absolute pressure. Gauge pressure takes into account fluctuations in atmospheric pressure.
Differential pressure
Differential pressure sensors are something altogether different. They are used to measure the difference between two different process pressures. Unlike gauge pressure transducers which measure two different, differential pressure typically refers to measuring difference in readings between two separate locations.
The vast majority of pressure transducers measure these types of pressure. If you are interested in learning more about which pressure transducer is right for you, please get in contact with the team at Applications Engineering today.
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