2. Electromagnetic flowmeter technology

2.1 Components

The sensor is the essential element, but it cannot be used on its own for several reasons: the flow voltage at the electrodes is low (it is measured in microvolts), so it must first be amplified; furthermore, it must be free of parasitic signals that would cause an unbearable error; from this voltage, a signal representative of the flow must also be generated, taking into account the value of the field in the measuring tube. This signal must be put into a form acceptable to the indicating and recording instruments. On the other hand, in some cases, it is necessary to produce the supply current for the inductors with the required characteristics.

All these elements have the common feature of being purely electrical, and make up what is known...