Accelerometers and Their Applications

An accelerometer is an instrument meant to measure the linear acceleration of a carrier, consisting of a proof mass, support, potentiometer, spring, damper, and a housing. It is a device that is able to measure the vibration or motion acceleration of a structure. Often composed of a piezoelectric material, an accelerometer is squeezed when it encounters vibrations and acceleration, which creates a charge that is proportionate to the force applied to it while the mass remains constant. Most cellphones feature accelerometers which can be seen at work when the device moves in different directions, such as when the screen automatically brightens as a smartphone is turned over. They assist engineers with understanding machine stability, ensuring unwanted forces and vibrations are not present in a system.

These devices are used to determine if a force is either static or dynamic. Static acceleration is a constant force exerted on an object like gravity (with an acceleration of 9.8 m/s) or friction, which are both consistent nearly everywhere on Earth. Non-uniform, dynamic acceleration forces like shock and vibration also exist; an example of this type of acceleration is a car accident, in which the acceleration change occurs at once. An accelerometer detects this acceleration by converting it to a measurable quantity like an electrical signal.

There are five different types of accelerometers: the piezoelectric accelerometer, piezoresistive acceleration sensor, capacitive accelerometer, three-axis accelerometer, and servo accelerometer. To start, piezoelectric accelerometers feature piezoelectric crystals which work by polarizing within when deformed by a force moving in a particular direction. These opposite-sign charges are formed until force is removed, and the crystals return to their uncharged state. This is known as the piezoelectric effect; these crystals often consist of quartz or piezoelectric ceramic, among other piezoelectric crystals. As the accelerometer vibrates, the force exerted by the mass on the piezoelectric element is altered, and this force change is in proportion to the recorded acceleration when the recorded vibration frequency is lower than the natural frequency of the accelerometer. A disadvantage of this type of accelerometer is that they are unable to measure zero-frequency impulses.

Another type of accelerometer is the piezoresistive acceleration sensor which is constructed as a silicon beam and mass block supported by a cantilever beam. When encountering inertial force, the mass block shifts upward and downward, while the resistance valve of the beam changes along with the action of the stress. This causes variations in the output voltage of the measuring bridge so that acceleration can be measured. This type of accelerometer comes in several different forms, including cantilever beams, double arm beams, 4-beams, and more. A third type of accelerometer is the capacitive accelerometer which features polar-distance-variable capacitive sensors; a single electrode is stationary, while an elastic diaphragm is displaced by an external force. This type of sensor measures the airflow vibration velocity, as well as the pressure. These accelerometers are usually used for low frequency measurement because they are not as cost-effective as their piezoelectric counterparts.

The accelerometer is widely used in drones, digital devices, vehicles, rotating machinery, industrial platforms, and vibration monitoring. At Integrated Aircraft Parts, we have more than two billion new, used, obsolete, and hard-to-find parts available to our customers for immediate purchase. As an AS9120B, ISO 9001:2015, and FAA AC 00-56B accredited parts distributor, you can trust in the caliber of our offerings. Many of the parts we offer are subject to rigorous quality assurance measures in order to guarantee their level of safety and effectiveness. Once you place an order with Integrated Aircraft Parts, our team works diligently to get your parts shipped out and delivered to you as quickly as possible. At your leisure, fill out and submit one of our online RFQ forms on our website and one of our dedicated account managers will get back to you with a quote for your comparisons in 15 minutes or less.