Experimental data on the reliability of flowmetrs for pressure pipes

This paper summarizes the results of a large number of tests carried out about the reliability of discharge measurements given by flowmeters for pressure pipes of different kinds (electromagnetic, ultrasonic and turbine flowmeters), on the basis of the experimental data collected at Laboratorio di Idraulica “G. Fantoli” of Politecnico di Milano. In fact, since 2002, this laboratory is the seat of the Settore Portate of Centro SIT n. 104, that is a structure of Politecnico di Milano accredited for flowmeters calibration in the discharge range from 3 l/s to 80 l/s, with a so-called “best measurement capability” (BMC) equal to 0.2 %. During these years, a lot of calibrations of different flowmeters have been carried out (61 flowmeters were tested so far: 44 electromagnetic, 9 ultrasonic, 8 turbine flowmeters). So, the tested flowmeters are supposed to give a relevant sample of experimental data, and therefore it seems interesting to carry out some statistical analyses about their performances and reliability. Of course no general consideration can be inferred about the general performances and reliability of other similar instruments not tested