Mass Flow Meter Features Dual Bent-Tube Design For Improved Stability

Nov. 15, 2012
The two tubes are made from C-22 alloy, which is less susceptible to thermal expansion than conventional stainless steel.

Yokogawa Electric Corporation RotaMASS LR is a small-sized, dual bent-tube Coriolis mass flow meter. The new RotaMASS LR represents an advance to Yokogawa’s RotaMASS Low Flow Line product family for gas and liquid flow measurement.

Designed to be self-draining and to measure both liquids and gasses, the mass flow measurement spans from 0-40 kg/h. The accuracy is +/- 0.15% for liquids and +/- 0.5% for gasses. Yokogawa has developed the low-flow Coriolis meter based on its dual bent-tube design to overcome the current shortcomings of single-tube, low-flow meters. These shortcomings include susceptibility to external vibrations and changes in ambient or process fluid temperatures which lead to less accurate and stable measurements in real-world conditions.

When fluid density changes, a single-tube Coriolis flow meter can become imbalanced and start to behave like an emitter. The RotaMass LR remains balanced due to the equal mass change in both tubes and the absence of interference from the process piping.

By design, it is insensitive to fluctuations in the ambient temperature and achieves zero stability under changing process conditions. The two tubes are made from C-22 alloy, which is less susceptible to thermal expansion than conventional stainless steel.