New flowmeter combines mechanical and electronic functions

Proven variable area flowmeter gains sophistication with digital signal processing technology. Solid state design electronically senses movement of the magnetic piston assembly and provides accurate, repeatable flow measurements. The device has no mechanical linkages, which results in longer operating life. While pre-calibrated, it still can be configured for...
By Control Engineering Staff April 16, 2009


New MR Flow Transmitter from Hedland combines state-of-the-art digital signal processing technology with the rugged proven technology of a piston-type variable area flow meter. The solid state design electronically senses movement of the magnetic piston assembly and provides accurate, repeatable flow measurements. The device has no mechanical linkages, which results in longer operating life.

All MR Flow Transmitters come pre-calibrated from the factory. However, the unit may also be user configured to meet specific application requirements. Calibration inputs are available for: specific gravity for all fluids, viscosity for petroleum-based fluids, as well as specific gravity, pressure, and temperature for pneumatic systems. Combined with user-selectable units of measure, these configuration functions allow for precise measurement without conversion calculations for unique applications. This helps overcome many of the drawbacks of mechanical direct-reading variable area flowmeters.

The company says the new line includes additional benefits and features:

  • Non-contact sensor electronics;

  • Digital flow rate and total flow indication;

  • Proportional analog output;

  • CE compliance, and unit also meets or exceeds U.S. and European standards from EMI/EMC; and

  • Low power consumption allows for 2-wire loop powered operation.

The MR Transmitters provide 0-5 Vdc, 0-10 Vdc, and 4-20 mA outputs, allowing for easy electronic integration. Optional remote display and signal processors are also available.

The F6700/F6750 Series Digital Display with integrated signal processor capabilities is offered to enhance the utility of the MR Flow Transmitters. In addition to remote flow monitoring, this unit can be configured to provide alarm processing and communication modes, including RS232, RS485, Modbus, Profibus and DeviceNet.

Read an earlier tutorial on variable area flowmeters .

—Edited by Peter Welander, process industries editor, PWelander@cfemedia.com ,
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