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Introduction of Accelerometer
An accelerometer is an electromechanical device that measures the acceleration of movement of pipes, equipment, or structures.
It is a very useful tool for vibration engineering and is often used for vibration measurements in industrial equipment. The force of vibration produces an electrical signal that is detected by an accelerometer sensor.
Accelerometers allow maintenance and inspection engineers to understand machine stability and monitor it to make future decisions. In this article, learn more about accelerometers, how they work, their features, choices, and types.
How Does Accelerometer Work?
Accelerometers use sensors to detect static or dynamic acceleration forces. Static acceleration results from constant forces acting on an object, such as gravity and frictional forces. These forces are known, uniform, and mostly easy to calculate.
On the other hand, dynamic acceleration forces such as vibrations and shocks are sudden, irregular and not easily predictable. Accelerometers can record and measure acceleration in one, two, or three axes and convert it to an electrical signal. Accelerometers are generally equipped with an internal capacitive plate. Some are fixed, others are attached to small springs. When an acceleration force is applied to the sensor, these plates internally move relative to each other, changing the capacitance between them. Acceleration is then determined from these capacitance changes.
Other types of accelerometers use a piezoelectric material that supplies an electrical charge (voltage) when accelerated. There are other types that use the piezoresistive effect, thermal bubbles, and light.
Different Types of Accelerometers
There are three main types of accelerometers to help the industry efficiently solve vibration problems through measurement. they are:
- piezoelectric accelerometer
- piezoresistive accelerometer and
- Capacitive accelerometer.
Now I will discuss about these 3 types of accelerometers in detail.
1. Piezoelectric Accelerometer
This type of accelerometer uses piezoelectric material to sense changes in acceleration and is used to measure shock and vibration. There are two types of piezoelectric accelerometers. High impedance charge output accelerometer and low impedance output accelerometer.
In high impedance charge output accelerometers, the charge generated by a piezoelectric crystal is directly connected to the instrument. The charging output requires special coordination and instrumentation. This type of accelerometer can also be used in high temperature applications (>1200 C) where low impedance models are not available. A low-impedance accelerometer consists of a small internal microcircuit and a FET transistor. These elements convert the charge into a low impedance voltage that can be easily connected to standard instrumentation. This type of accelerometer is commonly used in industry. The OMEGA(R) accelerometer is primarily this type of low impedance accelerometer.
2. Piezoresistive Accelerometer
Piezoresistive accelerometers are much less sensitive than piezoelectric accelerometers and are primarily used for vehicle crash testing. A piezoresistive accelerometer senses pressure applied to it and increases resistance proportionally.
3. Capacitive Accelerometer
Capacitive accelerometers are the most commonly used type of accelerometer. The acceleration of an object is determined by the change in capacitance.
Applications/Uses of Accelerometers
- Smartphones, tablets, and digital cameras use accelerometers to rotate the display based on the orientation of the hold.
- The accelerometer is responsible for deploying the airbag in the event of a vehicle crash. An accelerometer attached to a car sends out a signal when it receives a sudden impact.
- Drones use accelerometers to stabilize orientation in flight.
- Vibrations in all components of rotating machinery are measured by accelerometers and inspected to determine the cause of the vibrations. Industrial platform:
- Accelerometers are used to measure platform stability and pitch.
- Accelerometers have proven very useful for monitoring vibrations in equipment, piping, or other components.
- Athlete wearable devices include accelerometers and gyroscopes to track improvement.
- Doctors use accelerometers to check weight gain and monitor body movements. A heart rate monitor also uses this device. Even with accelerometers, zoologists track animal movements in the jungle.