The flow meter is a device for gas and liquid flow measurement (by volume or by weight). Measurement of a liquid quantity in a closed pipeline is applied most in industrial practice for liquid flow monitoring, proper batching, and energy consumption evaluation.
Thus, applications can be found in any type of industry business, including food, chemical, heavy or health-care industries. In our case, we offer volumetric flow measurement based on induction or oval-gear flow principles. Both variants may include compact meters or those with separated evaluating electronic units, or with/without a display.
Induction flow meters
Induction flow meters work on the principle of Faraday’s electromagnetic induction law. The velocity of a liquid flow represented by the movement of the conductor induces a voltage in a homogeneous magnetic field. Practically, this means that the medium measured in this way must have a minimum conductivity at least (essential minimum specific conductivity) so that the voltage proportional to the flow can be induced across the electrodes of the meter.
Advantages and applications
There are distinct advantages such as nearly zero pressure losses, measurement of very aggressive and strongly contaminated liquids, high invariability and metrology measurement stability, not affected by pressure, temperature, viscosity or by solids. Thanks to this, the meters are used with advantageously also in batching processes in all sorts of production units. Individual batches can be in a wide range of sizes and velocities with the repeatability from 0.2%. These systems can be even more complex ones with complete control adapted to operating conditions for the use of protective gloves, including elimination of interference from the environment with intrinsic active valve actuation.
Paddle wheel flow meters
Measuring with the paddle wheel belongs to the most widely used meters for measuring liquid media and flows by the velocity field method and it is designed for all liquids, including non-conductive ones. The separate paddle is completed with an evaluation unit with electronic contact giving pulses during the movements of the paddles along the sensing element, possibly according to the set flow-rate of the medium.
Advantages and applications
The fundamental improvement is the absence of any magnetic components for picking up the movements of paddles and thus much longer maintenance-free operation. The advantage is also a modest price, equalizing the lower accuracy of the meter at low flow rates. Based on the construction of the evaluation unit, the input can be a pulse, current (4-20mA) or a flow controller. The meter can be equipped with the adjustment button for a simple change of the pulse constant, the level of flow for 20mA (the 4mA output always corresponds to 0l/min flow rate) or for switching the velocity of the flux for the flow monitor.
- Induction flow meters
- Paddle wheel flow meters