Pressure sensors typically use diaphragms and strain gauge bridges to detect and measure the force applied per unit area. Key specifications include sensor functionality, minimum and maximum operating pressure, full-scale accuracy, and any device-specific features.
Pressure sensors are used to measure pressure to determine a range of different values and types of pressure, depending on whether the pressure measurement is performed relative to the atmosphere, vacuum conditions, or other pressure reference levels. Pressure sensors are instruments that can be designed and configured to detect pressure in these variables. Absolute pressure sensors are designed to measure pressure relative to a vacuum, and they are designed to have a reference vacuum enclosed within the sensor itself.
A key aspect of industrial pressure sensing involves comparing multiple pressure levels. Differential pressure sensors are used in these applications, which can be challenging because at least two different pressures exist on a single mechanical structure.
1. Liquid-free barometer sensor
A liquid-free barometer consists of a hollow metal housing with flexible surfaces at its top and bottom. Changes in atmospheric pressure cause this metal housing to change shape, and a mechanical lever increases the deformation to provide a more pronounced result. The degree of deformation can also be increased by manufacturing the sensor with a bellows design. The lever is typically connected to a pointer dial that converts the pressure deformation into a proportional measurement or records the pressure change over time. Liquid-free barometer sensors are compact and durable, and do not use liquids in their operation. However, the mass of the pressure sensing element limits the device's response time, making it less effective for dynamic pressure sensing projects.
2. Pressure sensor
A pressure gauge is a fluid pressure sensor that offers a relatively simple design and a higher level of accuracy than most liquid-free barometers. It measures pressure by recording the effect of pressure on a column of liquid. The most common form of pressure gauge is the U-shaped model, where pressure is applied to one side of the tube, causing liquid to flow out and resulting in a drop in the liquid level at one end and a corresponding rise at the other. The pressure level is represented by the height difference between the two ends of the tube and is measured according to a scale built into the device.
3. Sealing pressure sensor
When a pressure measurement relative to a reference value is obtained, but the sensor cannot be directly opened to that reference pressure, a sealed pressure sensor is used.
