Level Detection with Ultrasonic Sensors

Liquid measurement can be a demanding application, therefore selecting the most effective sensor technology is imperative. Ultrasonic sensors handle distance measurement or position detection of granules, fluids and powders. They measure fill levels, heights and sag without making contact as well as count and monitor the presence of objects. They are versatile, operate independently of color and surface finish, and are not affected by transparent objects that generate strong reflections or by dust, dirt and steam.

Ultrasonic Sensors can monitor and detect nearly any liquid including water, paint and varnish.

Ultrasonic Sensors operate with the propagation of sound waves providing a reliable detection source for level detection applications where liquid measurement monitoring is necessary. They have the advantage of being a non-contact sensor so there are no mechanical floats or arms that can retain residual liquid build up. This residual material can cause machine application downtime as interruption of production is needed to maintain and clean the mechanical monitoring system. Because the distance to the object is determined through a sound transit time, ultrasonic sensors have excellent background suppression. With their transit time measurement, ultrasonic sensors can record the measured value with precise resolution (some sensors to even 0.025 mm).

Ultrasonic sensors can provide minimum and maximum level measurements simultaneously.

An ultrasonic sensor is not affected by the color, transparency or glossiness of a surface. They can reliably detect bulk materials, liquids and material surfaces.

Good reflective materials include:

• Water
• Paint/varnish
• Wood
• Metal
• Plastic
• Stone/concrete
• Glass
• Hard foam rubber

Additionally, ultrasonic sensors provide the ability to have two independent outputs programmed into one sensor. This feature allows one independent output setting to indicate a minimum level and the second output to indicate a maximum level concurrently, providing constant feedback along with a voltage or current output.

The color, glossiness or transparency of an object does not affect an ultrasonic sensor’s detection ability.

Ultrasonic sensors are suitable for a variety of industries including: automotive, pharmaceutical, conveying, machine construction and much more. Additionally, ultrasonic sensors can be used in a wide array of applications, such as height and width measurement, presence verification, robot positioning, fill level monitoring, stack height detection and more.

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