About Rosemount mass flow meters

Temperature changes cause variations in the elastic modulus of the flow meter material, thereby affecting the mass. If the temperature changes significantly, it should be compensated for. Regarding installation, each type of mass flow meter from Rosemount comes with its own installation instructions that can be referred to. I can tell you some general knowledge regarding the installation of mass flow meters: When installing a mass flow meter, the following points should be taken into account: ① A mass flow meter measures by utilizing the vibration of sensors; to avoid external interference, the installation location should not have any significant sources of vibration, and reinforcement measures should be employed to stabilize the pipes in the vicinity of the instrument ； ② A mass flow meter relies on an excitation magnetic field to function; therefore, it cannot be installed near devices that generate strong magnetic fields such as large transformers, motors, or pumps. It must be kept at a distance of at least 0.6 to 1.0 meters from such devices to avoid interference ； ③ No stress (especially torque) should be present when connecting the sensor of the mass flow meter to the pipe; for this reason, the sensor must be welded to the properly supported pipe in a free state ； ④ Straight-tube mass flow meters should be installed vertically, so that the measurement pipeline can be emptied when the instrument is not in use, thereby preventing scaling. If installed horizontally, the two measurement tubes must be at the same level ； ⑤ When a bent-tube flowmeter is installed horizontally, if it is used to measure liquids, the housing should face downward to prevent gas from accumulating inside the measurement tube; if it is used to measure gases, the housing should face upward to prevent condensation from accumulating in the measurement tube ； ⑥ The connection cables for sensors and transmitters should follow the specifications in the manual. Since the transmitter receives low-level signals, the cables cannot be too long, and the manufacturer’s dedicated cables must be used.

Compensate for the factor that affects the stiffness of the flowmeter measurement tube due to temperature changes. Otherwise, the claimed precision cannot be achieved.

A mass flow meter – why would it need temperature and pressure compensation? Mass, as the name implies, is governed by the law of constant mass, and it has nothing to do with changes in temperature or pressure. This is something I’ve heard of for the first time; in all my time working with flow meters…