Benchmarking on the Accuracy of Multiple Clamp-On Transit-Time Ultrasonic Flowmeters

Clamp-on ultrasonic flowmeters became very popular in the industrial applications and they represent an interesting alternative to conventional flowmeters especially if the pipes cannot be modified or the process easily stopped. This work presents a study on the accuracy of seven clamp-on transit-time ultrasonic flowmeters coming from seven different manufacturers in both favorable and field-like measurement conditions. All tests have been conducted by EDF R&D on its liquid test rig EVEREST. In order to be representative of field applications, no access to reference flow rate during the installation of the flowmeters and no zero flow calibration were allowed. The entire measurement campaign implied around 100 installations and 600 flow rate measurements. The results showed that devices from different manufacturers have very different performances in terms of accuracy.