Dynamic calibration of flow meters using reference flow rate profiles generated by injectors

A new method to calibrate flow meters under dynamic conditions has been developed, based on the generation of variable reference flow rates using an automotive injection system. The method was tested with different flow profiles, including both idealized flow time-histories (sinusoidal and sawtooth waves) and actual fuel flow rate profiles recorded during WLTP (Worldwide harmonized Light vehicles Test Procedure) automotive type-approval tests. To demonstrate the effectiveness of the method, some results obtained with a Coriolis flow meter are presented. Compared with other methods such as those based on valves or volumetric pistons, the reference flow rate profiles obtained by the proposed approach feature dynamic characteristics (mainly flow oscillation time and gradients) that can be easily tailored to specific applications. The method has a high potential in evaluating the dynamic response of flow meters, which can be very different from that obtained with constant flow calibration.