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Gas flow sensor

For flow monitoring

Basic information

The electronic airflow monitor LW1-E indicates when flow rates fall below the required minimum. The device signals critical situations and produces a status message.


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

  • In air ventilation canals of machines and plants.
  • Laboratories.
  • Filter systems.
  • Clean rooms.

General function

The electronic air flow indicator works according to the calorimetric principle. It detects the flowing air and sends an equivalent electric signal. The heated sensor is cooled down by the flowing air. 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 air 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
  • extremely cost effective
  • housing according to customer‘s requirements
  • switching point adjustable according to required air flow conditions