Smart environmental monitoring solutions

Talk to our sales team. Call +61 2 9622 6327

Request a quote
Back to products

TunnelTech 202

CO, Visibility Monitor

The TunnelTech 202 Air Quality Monitor is an essential part of any road or rail tunnel safety system. Firstly, it monitors the atmosphere within the tunnel and ensures that the tunnel ventilation system provides sufficient clean air to protect tunnel users’ health and for drivers to clearly see the road ahead.

The TunnelTech 202 analyzer uses well-proven infra-red techniques to determine CO concentration and optical attenuation to monitor visibility levels. 


Have questions? Call +61 2 9622 6327


  • Continuous measurement of CO and Visibility in road and rail tunnels
  • Class-leading Accuracy, Repeatability, and Resolution
  • Rugged, corrosion-resistant construction
  • Minimal maintenance requirements
  • Optional RS 485 (Modbus) Output

Gas Species OptionsSingle or multi-gas measurements available: CO & Visibility
Measuring Unitsppm for CO, m-1 or m for visibility
Response TimeCO 2mins / Vis 10s – 2min Selectable
Ambient Temperature-20°C to +50°C
Power Supply12 – 24V dc 1.5A
ConstructionCorrosion resistant epoxy coated aluminum housing sealed to IP65
Analogue Outputs3 x 4-20mA current outputs as standard, isolated, 500Ω maximum load, fully configurable
through TunnelTech software
Relay Outputs3 x volt-free SPCO contacts, 50V, 1A max, configurable as alarm contacts
Series DataFor local connection to laptop PC using RS232 or optional RS485 interface unit


You have successfully subscribed to our newsletter!