Coriolis flow measurement is described as a direct or dynamic technique; it supplies a signal that is proportional to the mass flow, and practically independent of material properties, such as conductivity, pressure, viscosity, or temperature. A Coriolis force occurs when linear motion and rotary motion are superimposed on one another. In industrial systems incorporating this principle, mechanical vibrations occur at the point of rotary motion. Fluid flowing through two tubes causes the tubes to resonate. Cavitation should be avoided, as it can effect the vibration of the measuring tubes. Media, whose properties are similar to water under normal conditions, have no special requirements. However, media that tend to boil easily, namely hydrocarbons, liquefied gases etc, or with suction conveyance, care should be taken not to exceed the liquid vapour pressure, and cause the liquid to boil.