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Sensor Accelerometer: The Comprehensive Introduction you Need

Sensor Accelerometers detect shocks and vibrations of devices and measure the magnitude and the direction of the proper acceleration. Hence, you will find them in numerous electronic devices, aircraft, and other industries. This article will highlight the intricate details of sensor accelerometers and their application in our day-to-day lives. You are on the right page if you are an electronic enthusiast looking to learn more about accelerometers.WELLPCB dedicates itself to offering dynamic content regarding electronic components. 

What is a Sensor Accelerometer?

A sensor accelerometer is simply a device that identifies and quantifies the acceleration on a body in its instantaneous rest frame. 

What is Acceleration?

Firstly, acceleration is the rate of change of an object’s velocity (the displacement of the object/ change in time). Static and dynamic forces are the two types of acceleration. Static forces such as friction and gravity constantly act on an object. For example, if you put an accelerometer at rest on the ground, the acceleration of the Earth will show because of gravity. On the other hand, dynamic forces actively act on an object at various stages.

Sensor-Accelerometer Configuration

Also, an accelerometer is a dynamic sensor that measures acceleration in one, two, or three orthogonal axes. It functions in one of the three modes:

  • Measure velocity and position
  • Sensor inclination, tilt, or orientation in two or three dimensions
  • Sensor vibration or impact
a picture of a 3D cube indicating three-axis accelerometer

(a picture of a 3D cube indicating a three-axis accelerometer) 

Accelerometers on Micro-Electro-Mechanical Sensors (MEMS)

It is responsible for recognizing a device’s rotation, hence, ‘flipping’ the screen to the desired angle. You get most accelerometers in devices through MEMS, small mechanical and electro-mechanical elements. Because of their small sizes, you will find them in handheld and wearable devices like phones. 

A new generation of three-axis MEMS and gyroscope chip technology enables smartwatches to identify a variety of falling postures. Consequently, it could identify a fatal fall and inform emergency contacts to get help.  

Microphone Breakout

(Microphone Breakout)

How does the Sensor Accelerometer Work?

Sensor accelerometer works in two ways: piezoelectric effect and capacitance change. 

Piezoelectric Effect

A Piezoelectric sensor has a microscopic crystal structure that generates voltages when it detects acceleration. For example, there are vibrations, and the device will create voltage to indicate proportional acceleration. 

Such sensors are applied as tilt or pressure sensors in consumer electronics like mobile phones and touchpads. 

a schematic image of Piezoelectric sensor electrical model

(a schematic image of the Piezoelectric sensor electrical model)

Capacitance change

The capacitive sensing method uses the formula Force = Mass x to measure the acceleration of an object. Hence, it uses the Force present / Mass of the item in question. Capacitance effect in MEMS works when:

  1. There are two capacitive plates
  2. Object mass rests on one of the plates changing the capacitance, thus, measuring force.
  3. Hence, we get acceleration from the force and mass of an object 

3. The Main Application of Accelerometers

The world applies accelerometers in science and various industries that people benefit from extensively. From engineering, biology, and medicine to navigation and transport, sensor accelerometers play a huge part in our lives. 

  • Automobile safety: Sensor accelerometers are in automobile collision safety systems. For instance, if a vehicle experiences a powerful dynamic force, an embedded computer receives an electronic signal that deploys airbags during a collision.
image of deployed airbags in a car. Car safety.

(image of deployed airbags in a car. Car safety.)

  • Game control: In gaming, the accelerometer in the handheld control device detects tilting. Therefore, it is simple to control objects in the game. 
  • Machinery health: Engineers apply accelerometers vibration sensors in machine monitoring. Mechanical accelerometers devices report any vibrations or changes in rotating equipment such as turbines, pumps, fans, and rollers. Therefore, such data allows engineers and technicians to make necessary adjustments immediately. 

4.  How to Select the Appropriate Sensor Accelerometer?

For accurate measurements of acceleration, consider:

  1. Frequency response. What is the accelerometer’s electrical output vs. a mechanical excitation over a frequency range? Normally, a good frequency has a + or -5% (usually, 100 Hz).
  2. Several axes. You can mount three sensor accelerometers on a 3-axis mounting block to get three orthogonal axes.
image of Smartphone gyroscope icon flat vector. Phone accelerometer

(image of Smartphone gyroscope icon flat vector. Phone accelerometer)

conclusion

Finally, accelerometer sensors get the massive application on various subjects without concentration on sensor placement.  The widespread smartphone usage allows accelerometers usage for simple tasks like shake motion and screen orientation changes. Nevertheless, sensors of MEMs type find use in more complex tasks.

If you need more information regarding sensing technologies, we at WELLPcb are happy to point you in the right direction. 

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Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.

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