Coriolis Mass Flowmeter

A Mass Flow Meter operating on the “Coriolis principle” contains a vibrating tube in which a fluid flow causes changes in frequency, phase shift or amplitude. The sensor signal is fed into the integrally mounted pc-board. The resulting output signal is strictly proportional to the real mass flow rate, whereas thermal mass flow meters are dependent of the physical properties of the fluid. Coriolis mass flow measurement is fast and very accurate.

Coriolis flow meters work on the principle that the inertia created by fluid flowing through an oscillating tube causes the tube to twist in proportion to mass flow rate. Many Coriolis meters have two tubes. They are made to vibrate in opposition to each other by means of a magnetic coil. Sensors in the form of magnet and coil assemblies are mounted on the inlet and the outlet of both flow tubes. As the coils move through the magnetic field created by the magnet, they create a voltage in the form of a sine wave. These sine waves are the key to measuring mass flow.


Coriolis flow meters are the most accurate flow meters made. While many magnetic flow meters have accuracies in the range of 0.5 percent, many Coriolis flow meters achieve accuracy of 0.1 %. It is the high accuracy of Coriolis flow meters that is one of the major reasons for their extremely rapid growth over the past five years. Companies that need flow meters for custody transfer, or want highly accurate measurements in terms of mass, have a good reason to select Coriolis flow meters also very easy to installasi.


Coriolis Mass Flow Transmitter

Inside the measuring sensor, there are precision tubes that are energized by an electromagnetic drive system, which itself is fed by the transmitter, to vibrate at their natural frequencies. When a liquid or gas flows through the vibrating tubes, it is subjected to additional deflection due to the degree of inertia that is generated. This deflection is recorded electronically by two velocity sensors and a high-precision electronic time delta. This measured quantity is proportional to the mass flow rate. A further conversion into physical units is done in a purely digital manner using a signal processor in the transmitter. At the same time, all of the appliance’s functions are constantly monitored. Should any disruptions occur, all of the errors that have occurred are immediately reported in the display.

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The transmitter has a 4 to 20 mA analogue output with programmable span, which is proportional either to the measured mass flow rate or the temperature; it also has an impulse output that supplies mass-proportional impulses. All of the outputs and measuring functions can be verified at any time by the user by using the diagnostic mode in the appliance. The maintenance or new calibration intervals can be monitored via a run-time counter. For service or repair purposes, the transmitter and flow sensor can be replaced independently of each other.

The RHEONIK mass flow meter consists of one of the RHM series flow sensors and one RHE series transmitter. The remote unit RHE 07/08 is for installation in a safe non-Ex area and is connected to the sensor via a single multi-conductor cable. Please note, that the types RHE 07/08 and all sensor articles are available in non Ex-versions (without Exnameplate). The RHE 11 (Ex d) may be installed and operated in hazardous Ex-areas (Zone 1 or 2). Ex-series sensors RHM (with Ex-Label) are, when connected with an Ex- Transmitter, made for installation inside hazardous areas (Ex-zone 0, 1 or 2). The transmitter RHE includes seven printed boards which can be replaced during servicing. The remote electronic unit consists of two bent measuring loops in the shape of an omega.