Optical liquid sensors for tubes and capillaries

Balluff STM GmbH:Applied in the right way optical sensors generally offer a significantly better accuracy in the detection of liquids in transparent tubes or hoses than other physical methods. Capacitive or ultrasonic principles are reaching their limits, especially with small total diameters or with high wall thicknesses.

Different liquids as well as tube materials show, depending on their geometry, very different optical behavior. For this reason, there is a number of influencing variables in the application of light, which needs to be respected, to achieve reliable results. The right combination of utilized wavelength, optical quality, and orientation of the light beam is decisive for the accuracy and reliability of the detection.

STM offers a family of sensors for liquid detection in transparent containers, tubes, and hoses which combine these parameters, according to the application, in an optimal way. The variety of applications can range from level detection in semi-transparent containers up to microbubble detection in capillaries or microfluidic channels.

With all sensor versions, the patented microoptical precision components from STM are the key to the high-detection reliability. The different body designs aim for optimal usability with minimum installation and adjustment effort.

Simply because the best solution may not always be initially obvious, we are happy to check your application in our lab to help find the ideal setup. Free of charge technical advice from our specialists is part of our customer service. Due to the modular design of our sensors, customization can be provided at short lead times and at a very reasonable cost.

P.S.: In combination with a dynamic amplifier from STM, the flow of granulated solids in clear tubes or hoses may also be monitored.