Experimental study on the closed-loop control system of Coriolis mass flowmeter for oil-water two-phase flow measurement

Coriolis mass flowmeter (CMF) is significant in many industrial and commercial areas. The two-phase flow, external vibration or flow pulsation in a Coriolis mass flowmeter can cause errors in the meter´s measurements of density and mass flow rate. Some errors may be due to the closed-loop control system. In this paper, they are investigated from analog and digital closed-loop control system by experiment study. And also the advantage and disadvantage ware tested between analog and digital closed-loop control system by using the oil-water two-phase flow. It was found that the relative precise error of mass flowrate was relatively small for oil-water two-phase flow, not changed with the quantity of oil. Experimentally-derived data was used to illustrate that the digital closed-loop control system has more precise than the analog, and provide stable oscillation and selection of a sustainable setpoint for amplitude of oscillation, even during situations such as a highly-damped operation of the flowtube, vibration or beginning/ending operation of the flowtube.