The TunnelCraft ll AQM CO/VIS sensor uses infrared light to measure Carbon monoxide. It consists of a transceiver that projects an infrared beam to a reflector unit mounted 3m away. The energy is reflected back and the specific absorption is measured to determine the carbon monoxide concentration within the path of the beam. Where a visibility channel is required, a separate visible light transmitter and receiver are incorporated into the same transceiver.

- Quality and Construction
  Designed to withstand the harshest of tunnel environments