CORIOLIS FLOWMETER

摘要

A Coriolis flowmeter capable of solving problems with a conventional flowmeter wherein when outputs from two vibration detection sensors are measured in the form of phase difference time, a tube must be thinned to increase the sensitivity thereof to a measurable degree and accordingly flow velocity is increased, pressure loss is increased, and the thickness thereof must be reduced, and therefore the pressure resistance thereof is difficult to increase, particularly, the sensitivity of signals against a flow is difficult to increase and, accordingly, gas flow with low density cannot be accurately measured. A Coriolis vibration frame (16) carrying a U-shaped tube is swingably fixed to a forced vibration frame (19) fixed to a support base (22) to form a highly rigid frame structure limiting a vibrating direction to one degree of freedom in a Coriolis vibration direction. The forced vibration frame (19) is vibrated by a vibration exciter (20) so that the ratio of a forced frequency to the Coriolis frequency of a pipeline is approximately at least 1 to 10. The ratio of the amplitude of the forced vibration to the amplitude of the Coriolis vibration is calculated based on signals from two vibration sensors such as acceleration sensors (17) and (18) to measure the mass flow of fluid flowing in the pipeline.