CODEL International’s new TunnelTech 305 Air Flow Monitor designed exclusively for road and rail tunnel applications builds on years of experience and proven technology.

The TunnelTech 305 not only monitors the air flow measurement inside the tunnel it also monitors the direction of the air flow and temperature. This ensures that the tunnel ventilation system provides enough clean air to protect the health of tunnel users as well as enabling drivers to clearly see the road ahead.

A recent Wind Tunnel Test was carried out at the HSE Laboratory in Buxton, Derbyshire to test and compare measurement capability of the Air Flow Monitor against calibrated air flow measurement fitted in the wind tunnel. The test results demonstrated excellent performance from the monitors with a response as shown in the results below.

Velocities of 0, 5, 10 and 20 m/s were generated inside the test tunnel and then repeated with the air velocity sensors rotated through 180 degrees.

Below are the results from two tests:


TunnelTech 305 Wind Tunnel Test

TunnelTech 305 Velocity



TunnelTech 305 Wind Tunnel Test

TunnelTech 305 Velocity



The Air Flow Monitor uses dual path ultrasonic technology to ensure high accuracy over a wide measurement range and, with no moving parts, results in extremely high reliability levels and very low maintenance requirements.

To stay updated on the TunnelTech 305 Air Flow Monitor, follow us on Facebook, LinkedIn and at

TunnelTech 305 Series