Ultrasonic Proximity Sensors

Ultrasonic proximity sensors are a type of non-contact sensor. They use transmitted or reflected ultrasonic waves to detect whether an object or material is present or absent. They are reliable and versatile and can be used reliably in almost all conditions.

How do they work?
These sensors work by emitting a short bust of ultrasonic sound at a specific frequency towards the target. When the target reflects the sound back to the sensor, the sensor measures the time it takes for the echo to return. The sensor will use the time it takes the soundwave to travel back to calculate the distance between the sensor and the object.

What are they used for?
Typical applications for these ultrasonic sensors include stacking height control, irregular part detection within hoppers and feeder bowls, automotive assembly and loop control. Other suitable applications include thread or wire break detection, robotic sensing, detection of people for counting and liquid level control.

Things to consider
When deciding which sensor you should choose, there are a few things that you should bear in mind. Ultrasonic proximity sensors can be affected by noise interference and some will have a blind zone at close proximity. The surface angle of the target, and the roughness of the target surface can also affect the sensor. Some materials such as cloth or carpeting can absorb soundwaves rather than reflecting them. The speed of sound can be affected by temperature and humidity which can impact the resolution and accuracy of the sensor.