Electronic flow switches offer the operator a local display of the flow values and, at the same time, an output of an electrical signal (PNP, NPN or 4-20 mA) for transmission to a remote control room. Thus, flow switches are used for the display and monitoring of the flow of liquid and gaseous media.
Electromagnetic flow meters
Electromagnetic flow meters are used to precisely measure conductive liquids. The measuring principle is based on Faraday’s law of induction. According to this law, a conductive liquid can be measured by its voltage as it passes through a magnetic field. The advantage of electromagnetic flow meters is that they work even in the absence of power supply and can be used regardless of pressure, temperature, density, viscosity and aggressiveness of the measured substances.
Air flow sensors
For the monitoring of air flows in ventilation and air-conditioning systems, flow sensors are suitable for volume flow calculation based on the measured differential pressure and the fan constant (K factor) of the connected radial fans. The exact measurement of the smallest differential pressures is crucial for the cost-effective and technical monitoring of room air systems. Here, PI controllers and pitot tubes are also used for this application.
