D8LB

The measuring system operates on the Coriolis measuring principle. The Coriolis force acts on an object moving linearly within a rotating system. Fc = 2 · ∆m (ν · ω) Fc =Coriolis force ∆m =mass of the moving object ω =angular velocity ν = radial velocity of the object within the rotating or oscillating system The magnitude of the Coriolis force depends on the mass \(\Delta m\) of the moving object and its radial velocity v, i.e. the mass flow rate. Instead of a rotating system with constant angular velocity \(\omega\), the sensor uses oscillating measuring tubes.Fluid flows through the sensor. Two parallel measuring tubes inside the sensor oscillate in antiphase, similar to a tuning fork. Coriolis forces are generated within the measuring tubes and create a phase shift in tube oscillation: • At zero flow (fluid at rest), both measuring tubes oscillate in‑phase with no phase difference. • Under mass‑flow conditions, oscillation accelerates at the tube inlet and decelerates at the tube outlet, generating a phase shift.The phase shift increases with rising mass flow rate. Electromagnetic phase sensors record the oscillation phase at the inlet and outlet of the measuring tubes. Antiphase oscillation of the two measuring tubes ensures mechanical system balance. The measuring principle is completely independent of temperature, pressure, viscosity, electrical conductivity and fluid properties.

Liquefied Natural Gas (LNG) Applications

LNGmass is a Coriolis mass flowmeter specially developed for LNG dispensers. It guarantees highest accuracy and stability even at extremely low process temperatures down to –196 °C (–321 °F). Thanks to its extremely compact design, the device can be installed almost anywhere, even in the most confined spaces. LNGmass features no moving parts and is maintenance‑free. • Coriolis mass‑flow measuring principle independent of fluid physical properties such as viscosity and density • Precise metering of cryogenic liquefied natural gas within LNG dispensers