The use of a venturi meter for the measurement of refrigerant liquid-vapour mass flow rate in a horizontal pipe is prevented. Various models that utilise the output of the venturi flowmeter and the measured void fraction and/or quality to calculate the two-phase mass flow rate were examined. It was found that the applicability of the various models is dependent on the quality range. When the quality is less than 50%, the use of the momentum density model provides the best accuracy. For higher qualities, the use of the homogeneous equilibrium model is recommended.

KEYWORDS: year 1995, measuring, refrigerants, fluid flow, flow rate, flowmeters, venturi meters, horizontal, pipes, calculating, accuracy, comparing, testing, refrigeration