ADXL 3xxx Accelerometer

Translational-motion inertial sensor. Attach:ADXL.gif Δ Attach:file.ext Δ

An accelerometer output is a variable voltage depending on the amount of acceleration applied.

The common reference is the resultant acceleration produce by earth’s gravity force.

The unit used for the acceleration measure is g, the earth’s gravity at sea level.

1g = 9.8 m/s2

Their outputs need to be integrated once with respect to time to get velocity and integrated twice to get position (Question)

Uses:

Inertial measurement of velocity (position)

Sensor of inclination, tilt or orientation

Vibration or impact sensor

Type:

Differential capacitive

Output a voltage dependant on the distance between two planar surfaces.

One of the surface are charged with electrical current, the change in the

gap between the plates changes the electrical capacity or the system.

Specifications:

Number of axes: 3 axis

Senor Input: ±3 to ±3.6 g

Sensitivity: 270 – 330 mV/g

 (Voltage output per g)An indicator of the amount of change in output signal 

for a given change in acceleration expressed in terms of volt per unit of acceleration.

Is the Ratio of an electrical output to the mechanical input. RADIOMETRIC

Amplitude stability:

Changes in sensitivity in temperature or time

Zero g offset: 1.2 –1.8 V

(Voltage output at 0 g) It is specified for the position of the sensor where is active axis is perpendicular to Earth’s gravity.

Frequency response:

 It is the output signal over a range of frequencies where the sensor should operate.

Bandwidth: X and Y = 1600 Hz Z= 550Hz

 Indicate how often a reliable reading can be taken. (Hundreds of hertz for vibration)

Output amplifier: Low 0.1 V – High 2.8 V

 (Maximum and minimum swing) \\ 

Power Supply: 2- 3.6 V

Power consumption

Temperature range: -25 to 70 °C