The TunnelTech 301 Air Flow Monitor (AFM) is CODEL's industry proven tunnel air flow monitor. Tunnel ventilation systems are designed to enable a sufficient throughput of air to be maintained to ensure a safe operating environment for users. These systems consume large amounts of power and need to be operated as efficiently as possible. To do this it is necessary to know the effectiveness of the system in terms of air flow and direction developed within the tunnel.

Three decades of development, knowledge and practical experience have been utilised to produce the advanced TunnelTech 301 air flow sensor that combines the reliability of ultrasonic technology and delivers superb accuracy and reliability at a very competitive price.

Key Features

  • Single point ultrasonic measurement • technology
  • Unaffected by traffic flow and sound reflections
  • No moving components providing maintenance free operation
  • Designed to withstand the harshest of tunnel environments
  • Measurement precision of +/- 0.2m/sec


SpecificationImagesDocumentationProduct Enquiry



Measurements Air flow and direction
Measuring units m/sec
Measurement Technique Ultrasonic
Ambient Temperature -20°C to +50°C
Power supply 12V DC @1.5A
Construction Corrosion resistant epoxy coated aluminium housing sealed to IP65
Analogue outputs 2 x 4-20mA current outputs as standard, isolated, 500Ω maximum load, fully configurable
through TunnelTech software.
Relay Outputs 2 x volt-free SPCO contacts, 50V, 1A maximum load, configurable as alarm contacts
Serial Data For local connection to laptop PC using RS232 or optional RS485 interface unit
Lang Filetype Document Size
English TunnelTech 301 Datasheet 400kb

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