TOSHIBA ELECTROMAGNETIC FLOWMETERS
Application
These flowmeters are ideal for all conductive liquids including aggressive, abrasive and corrosive chemicals, hygienic liquids and liquids containing solids. Typical applications include the measurement of pharmaceuticals, chemicals, pulps, foods, acids, alkalis, dyes and waste water. The accuracy is not affected by changes in pressure, temperature, density, conductivity or viscosity. The flowmeter will accurately measure uneven flows.
Output
An LCD displays the flow rate and the total. There is also a 4-20mA analogue and two pulsed signals for transmitting to control systems or remote instruments. There are options for high and low flow alarms, empty pipe detection, preset point output, multi-range selection and forward and reverse flow detection. The outputs are HART compatible for remote communication.
Construction
The meter is made up of a detector and display which you can mount either together or separately. There is no obstruction to flow so any solids simply pass through and the pressure drop is very low. The technology used gives outstanding accuracy, stability and reliability. A build up of deposits on the electrodes has no effect on the readings provided some part of the electrode is exposed.
Calibration
To increase accuracy the operating range can be set to any value between the minimum and maximum flow ranges. A test certificate is issued for each flowmeter and the display and outputs are preset to your requirements.
Installation
The flowmeter detector is mounted in the line and should be maintained full of liquid. It should be installed with ten straight pipe diameters upstream. The combined model has an integral detector and display. The separate model allows you to mount the display away from the detector.
Principle of Operation
The measuring principle is based on Faradays Law of Electromagnetic Induction which states that if an electrical conductor, in this case the measured liquid, passes through a magnetic field an electromotive force (EMF) is induced perpendicular to the field and flow.
This EMF is proportional to the average flow velocity and is detected by two electrodes mounted in the detector. The signal is conditioned by the converter to display the flowrate.
