Common Types of Pressure Sensors and How They Work

Pressure sensors are devices used to measure pressure and alert a computer system via an electrical signal. As the most commonly used sensors in industrial construction, they are used in various environments, including for hydropower, railway transportation, intelligent buildings, production automatic control, aerospace, and military operations, among others. Within these sectors, the sensors may be used for measuring the pressure of a system and/or for alerting an operator when issues arise. To fit such a wide selection of environments, there are several types of pressure sensors to choose from, including piezoelectric, strain gauge, ceramic, sapphire, and diffused silicon, all of which are explained here in this blog.

Common Types of Pressure Sensors

Piezoelectric Pressure Sensors: As the name suggests, these sensors rely on the piezoelectric effect, a phenomenon which describes how certain crystals respond to pressure. Derived from the Greek word πι?ζειν (piezen), which means to squeeze or press, piezoelectricity is the word given to the electric charge that is generated in certain solid materials–like crystals–in response to applied mechanical pressure or stress. Therefore, piezoelectric pressure sensors are those which can observe this electric charge in a crystal or other material as an input, sending an output signal in response.

Strain Gauge Pressure Sensors: A strain gauge sensor is a device used to measure the strain of an object, that is the deformation produced by the influence of stress. Of the various types, the most commonly used resistance strain gauges are metal resistance strain gauges and semiconductor strain gauges. These types both consist of either a metal foil strip, flat length of metal wire, or a strip of semiconductor material which can be stuck onto surfaces like a postage stamp. When the wire, foil, strip, or semiconductor is stretched, its resistance changes, indicating that there has been a change in pressure.

Ceramic Pressure Sensors: Because of their unique construction and ceramic’s chemically inert nature, ceramic pressure sensors can withstand harsh atmospheric conditions and remain effective for a long service life. As such, they make up the core element of these sensors which measures the change in resistance that comes as a result of applied pressure. These sensors typically consist of a thick film resistor, printed on the back of the ceramic diaphragm, that is connected into a wheatstone bridge. Due to the way that ceramic reacts to pressure, once the sensor is exposed to pressure, it causes a slight deformation of the diaphragm. Called the piezoresistive effect, this deformation affects the resistance of the varistor, and the wheatstone bridge measures the resulting resistance.

Sapphire Pressure Sensors: Using silicon-sapphire as a semiconductor-sensitive element, the sapphire pressure sensor measures changes in the silicon-sapphire element to calculate pressure. This sensor is particularly useful because it is not sensitive to temperature changes, allowing the device to work where many other sensors cannot.

Diffuse Silicon Pressure Sensors: The diffused silicon pressure sensor also works based on the piezoresistive effect. Using this effect, the pressure of the measured medium directly acts on the diaphragm of the sensor so the diaphragm produces a micro-displacement proportional to the pressure of the medium.

Applications of Pressure Sensors

Pressure sensors are frequently used in commercial weighing systems, measuring devices, and water treatment equipment, among other applications. They are generally helpful for observing changes in pressure and conveying information to the computer or engineer. In industries that handle fluid transfer, this can be especially important as the pipelines often depend on pressure as a central way of creating movement, or even controlling the temperature of a fluid. Aside from this, they are also used in the medical equipment market where they can be used to help limit trauma to surgical sites.

Conclusion

Pressure sensors are useful as a way to measure and observe pressure changes in a plethora of applications. If your project requires pressure sensors or other industrial hardware, you can rely on Hardware and Fasteners. As a leading supplier of sensors, fasteners and other aviation parts, we are well-equipped to support you for all your operational requirements, even for AOG situations. Explore our catalog of aviation parts at your leisure, or use the search tool to find a particular component. Using our Request for Quote (RFQ) form, you can always request a competitive quote for your comparisons on any items that spark your interest. With representatives on standby 24/7x365 to answer customer inquiries, we guarantee a custom reply in just 15 minutes or less of receiving your completed RFQ form!