If you look at your speedometer when driving your car, the speed will let you know how quickly you will be able to get from one place to another. However, acceleration is much more interesting than speed and more useful because it can help you to know how quickly something can speed up or slow down.
Measuring acceleration requires figuring out how speed changes over a period and is usually measured with an accelerometer. These devices were once found only in jumbo jets and space rockets, but now they are in just about every car, many laptops, and in many other devices such as smartphones and tablets.
Applications of Accelerometers
Accelerometers used in spacecraft not only measure changes in rocket speed but when it is farthest from the Earth, as its acceleration due to gravity is at a minimum, and orientation, as titling, can be the result of some way gravity or other forces have acted upon it.
A more down-to-earth use of accelerometers is in automobile airbags as when an accelerometer detects a sudden change in a car’s speed, signaling an imminent collision; it triggers an electrical circuit that makes the airbags inflate.
MP3 players, cell phones, and handheld game consoles also most likely have an accelerometer built into them so they can detect when the device is being titles from one side to another. This is how these devices can figure out when to change the orientation of the screen from portrait to landscape.
Types of Accelerometers
There are mechanical accelerometers which have a mass attached to a spring suspended inside an outer box. When they sense acceleration the outer box moves immediately but the inner mass lags behind and once it moves, the spring stretches with a force that corresponds to the acceleration. How far the string stretches is used to measure the acceleration and the force.
There are other accelerometers that measure force by generating electrical or magnetic signals. In accelerometer that use piezo-electric crystals, such as quartz, the mass is attached to the crystals so when the accelerometer moves, the mass squeezes the crystal and generates a tiny electric voltage. Piezo-resistive accelerometers have the mass attached to a variable resistor rather than a spring and these resistors turn an electric circuit up or down depending on the size of the force.
Accelerometers in and of themselves may seem may not seem all that interesting but when you think about much they are found in our daily lives, it seems that engineers have come up with many ways to make really useful products with them.
For more than three decades, Watson Industries has produced accelerometers and solid state gyroscopes and provided engineering services and economical custom products around the globe. To learn more about the company’s products, please visit www.watson-gyro.com.
