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Liquid flow sensor

For flow monitoring

Basic information

The electronic flow indicator SW1 is available in various housings and connections and indicates when flow rates fall below the required minimum.


The electronic flowmeter is used where flow must be maintained above the minimum required flow rate, e.g.:

  • Pipelines of all types
  • Laboratories
  • Filter systems
  • Purifying plants

General function

The electronic flow indicator works according to the calorimetric principle. It detects the flowing medium and sends an equivalent electric signal. The heated sensor is cooled down by the ambient medium. Thus a change of current is generated in the semi-conductor sensor. This change is analysed by electronic devices which energise a relay. If the flow drops below the minimum required flow, the relay drops out. A relay change-over contact and an additional light emitting diode (LED) signals this situation.


  • compact package
  • 24VDC feed-in
  • extremely cost effective
  • self-sealing NPTF-thread
  • freely adjustable switching point for relay 230VAC/1A