Clamp-on tubing flowsensors are form-fitted to the outside of flexible medical grade and laboratory tubing, fastening securely around its circumference. No physical contact is made with the fluid media, so these sensors provide non-invasive measurement. Applications include most non-aerated liquids (e.g. blood, saline, cardioplegia, buffers, and water) flowing through most types of non-reinforced flexible tubing (e.g. PVC, Polyurethane, Silicone and other similar materials). Importantly, clamp on sensors do not break circuit sterility. 

Transonic Flowsensors are sized specifically for the outer diameter of the tubing application and are available in common tubing sizes from 5/32” to 1.25”. The flow sensor must be matched to the outer diameter of the tubing since the tubing is pressed into a rectangular shape in the measurement zone to provide a flat interface with the ultrasound crystal transducers. This prevents the “lens effect” seen in round tubing sensors, which intensifies the sensitivity near the center of the lumen but can leave areas near the edges unsampled. 

Utilizing transit time ultrasound technology, four crystal transducers pass ultrasonic signals back and forth through the tubing, and the resulting transit times are used to calculate volume flow. The four-crystal design provides extremely uniform sensitivity across the entire tubing lumen, creating flow measurement that is largely unaffected by turbulence. These sensors have become the standard for OEM medical design because they provide high accuracy and stability, even in challenging environments.