Flow measurement instruments

The compact device solution for non-contact flow measurement in tunnels

Your Benefits

  • Minimal wear and long maintenance intervals
  • Reliable measurement even at low air velocity
  • Low investment costs
  • Minimum installation costs
  • Easy integration into monitoring systems

The exact device specifications and performance data of the product may deviate from the information provided here, and depend on the application in which the product is being used and the relevant customer specifications.
In accordance with Article 2 (4), this product does not fall within the scope of RoHS directive 2011/65/EU and is also not designed for use in products which fall within the scope of this directive. You can find additional information in the product information.


The compact device solution for non-contact flow measurement in tunnels

The VM400 flow velocity measuring device is a compact and space-saving device solution for continuous point-to-point measurement of the air velocity in road and railway tunnels or comparable traffic infrastructure constructions. The VM400 can be assembled easily at nearly any point on tunnel walls. The measured values and status information are transmitted to a monitoring system via the integrated analog or digital interface, as wells as via an Ethernet interface in the VM400E variant.

At a glance
  • Modern ultrasonic technology for non-contact measurement
  • Large measuring range
  • Compact device design
  • Very easy mounting and commissioning
  • Immune to contamination


Technical overview

  • Technical data overview

    Technical data overview

    Measured valuesAir velocity, Direction of flow, temperature
    Measurement principleUltrasonic transit time difference measurement
    ConformitiesRABT 2006
    Enclosure ratingIP66 / IP67
    Type of fieldbus integrationRS-232
    FunctionProprietary service interface
    RemarkVM400E only
    FunctionConnection to SOPAS ET software
All technical data can be found accompanying the individual product