Thank you for purchasing the Smart Wireless 3 Axis Accelerometer Sensor. We pride ourselves on producing high quality products that meet with the demands of the busy classroom environment. If you have any problems using this sensor, please read this documentation in full before contacting the Data Harvest support team. 



Overview

The Wireless Smart 3 Axis Accelerometer Sensor is USB and Bluetooth compatible. Using Bluetooth, a sensor can connect to mobile devices, tablets, laptops, and desktops. 


The Accelerometer consists of acceleration sensing circuits set at right angles to each other, each measuring acceleration along one axis.

The sensor element is a capacitive device. A central mass is held static while suspended interleaved plates are free to move relative to this mass. The result is that any movement will create a change in position of the suspended element relative to the static mass, this changes the capacitance. The change in capacitance is proportional to the force – acceleration.

With a wireless sensor any connection back to the recording device will not suffer from problems of tangled wires.

An accelerometer is an electromechanical device that will measure acceleration forces. These forces may be static, like the constant force of gravity pulling at your feet, or dynamic - caused by moving or vibrating the accelerometer. It is able to detect the magnitude and direction of the acceleration. Accelerometers are common devices but are usually unseen and unnoticed.


    • A modern car’s airbag system uses acceleration sensors to determine the trigger point for release.
    • Seat belt tensioners in a car are often triggered by accelerometers.
    • Portable computing devices e.g. laptop computers, use accelerometers to lock hard drives if the computer is dropped.
    • Mobile phones use an accelerometer to determine the orientation of the screen and to adjust the screen resolution and mode.
    • Gaming consoles use accelerometers in the hand controllers.
    • As an accelerometer can be used to measure vibration, it can be used to detect the change in vibration signature of a machine as it starts to fail e.g. a motor bearing has a characteristic vibration pattern, smooth and quiet when in good order, gradually getting rougher and noisier as it wears out. 


An accelerometer does not measure gravity - it measures the component of "total acceleration minus gravity" along its input axis as "non-gravitational" acceleration (the acceleration it experiences relative to free-fall). 

 The term 'g - force' is normally used as shorthand to describe the force acting on a moving object relative to the force felt by an accelerating object at the earth’s surface. It is not an SI unit; it is used to express the relative force experienced. To convert to a correct SI unit all g values should be multiplied by 9.81 to it's m s-2 value.


Astronauts, fighter pilots, and racing drivers are often said to experience a force of so many 'g' when performing a particular manoeuvre. This force is rarely gravitational as it’s a rocket, jet, or combustion engine that provides the force needed to accelerate e.g. when a pilot changes speed or direction, or a racing driver goes around a corner. The effect of high acceleration on humans can be significant as most will lose consciousness if subjected to a sustained acceleration of between 5 to 7 g. This effect is only felt if the acceleration is sustained, i.e. jumping onto a hard floor can produce a deceleration of many g but only for a fraction of a second.