You have almost certainly encountered both an accelerometer and a proximity sensor. But are you able to tell the difference between these two types of sensors accurately? If you read on, you will be soon.

Accelerometer and proximity sensor comparison

Your phone uses an accelerometer to detect when you tilt your phone to the side and change the display orientation accordingly. Accelerometers detect movement in three dimensions, and this is just a special case of that.

A proximity sensor uses some kind of wave to detect the presence of nearby objects without touching them. You might encounter them in modern cars, automatic doors and a number of other everyday applications.

Of course, both of these sensors have a lot of everyday and industrial applications. This table will help clear up the main differences between an accelerometer and a proximity sensor.

Accelerometer

Proximity sensor

Definition

An accelerometer measures acceleration, both static and dynamic. Static usually refers to a force like gravity. And dynamic means movements like tilting or turning your phone. A proximity sensor can detect a variety of nearby objects without coming in contact with them. It often uses electromagnetic radiation.

Purpose

Safety and convenience. For example, in cars, accelerometers activate airbags in crashes. And in laptops, they protect hard drives from damage if they fall. Also safety and convenience. In your car, proximity sensors keep you from hitting the curb or a bystander.And on your phone, these will turn your touchscreen off if you hold it to your ear.Plus, in industry, they can keep separate parts from clashing.

Mechanism

The two most popular accelerometers are piezoelectric and capacitive.
The first has teeny crystals that react to acceleration, and this reaction creates a voltage. So the device interprets that voltage to figure out velocity and orientation.The second can sense static (like gravity) and dynamic (like human movement) acceleration. So a change in force will change its capacitance. Then the device can translate that into voltage.
An inductive proximity sensor has an oscillator that creates a fixed wave to drive a coil. Then the coil uses a ferrite core to create an electromagnetic field. So an object that breaks this field reduces the voltage and triggers a signal to activate.

Applications

You can use accelerometers to monitor vibration in machines and buildings or acceleration in vehicles.And in biological sciences, you can track animal behavior.They’re also used to guide inertial navigation systems and monitor active volcanoes. Proximity sensors guide cars in parking and alert pilots to ground proximity in flight. You’ve also seen them activating automatic sinks.
But did you know they monitor camshafts in some engines? And they detect vibration of rotating shafts in heavy machinery too.

To know more about accelerometer and a proximity sensor, please ask our engineers!

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