Luminance photometer for tunnels

The LUMIOS MkIII measures the level of luminance, or brightness, at the tunnel entrance / exit to ensure that the visual perception of drivers is maintained.


Natural light measurement
Measurement of luminance, or brightness, created by natural light at the tunnel portals
Viewing angle
Variable viewing angle within a range of 10 to 40º (factory preset)
Silicon photo diode
Silicon photo diode, Vλ filtered for spectral response close to that of the average human eye
Rugged construction
Rugged 316 stainless steel construction with IP66 protection rating
Heated window and enclosure
Luminance's measurement
Suitable for measurement of luminance within the tunnel

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The LUMIOS-MkIII measures the level of brightness or luminance created by natural light around tunnel portals. When integrated with a managed tunnel lighting system, the measurements provided by the LUMIOS-MkIII will ensure that the visual perception of drivers is maintained during the day and at night. This avoids sudden variations in lighting and potential “black hole effect” when entering and exiting a tunnel. .

The LUMIOS-MkIII has onboard SCADA / PLC interface options, including Current Outputs, Digital Relays and RS485 (Modbus RTU). The viewing angle can be specified between 10° and 40°. Optional wipers and pumped washer systems are also available for more demanding environmental conditions. The LUMIOS-MkIII is available with both AC and DC power supplies.


  • Designed specifically for monitoring tunnel portals
  • Rugged design to withstand extremes of weather conditions
  • Simple installation and mounting
  • Optional wash-wipe facility to minimise maintenance requirements
  • Flexible integration options
  • CIE Approved measurement of L20
  • Self-contained intelligent analyser for direct connection to host controller


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