Luminance at Tunnel entrance Sensor



  • Measurement of luminance, or brightness, created by natural light at the tunnel portals
  • CIE Approved measurement of L20
  • Variable viewing angle within a range of 10º to 40º (factory preset)
  • Silicon photo diode,Vλ filtered for spectral response close to that of the average human eye
  • Rugged 316 stainless steel construction with IP66 protection rating
  • Heated window and enclosure
  • Self-contained intelligent analyser for direct connection to host controller
  • Suitable for measurement of luminance within the tunnel

Luminance at Tunnel entrance Sensor


  • Designed specifically for monitoring tunnel portals
  • Rugged design to with stand extremes of weather conditions
  • Simple installation and mounting
  • Optional wash-wipe facility to minimise maintenance requirements
  • Flexible integration options


The GEO-LUMIOS measures the level of luminance, or brightness,created by natural light at the tunnel entrance/exit to ensure that the visual perception of drivers is maintained,both day and night, by avoiding sudden variations in lighting levels and potential “black hole effect” when entering and exiting a tunnel. The GEOLUMIOS can also be used for the measurement of luminance within the tunnel.


The GEO-LUMIOS uses a specially designed highly light -sensitive photocell,filtered to provide a spectral response close to that of the average human eye, to react to changes in light levels at the entrance and exit to,as well as within,the tunnel environment. This reaction is virtually instantaneous. The light receptor measures the average luminance within a fixed viewing angle that can be set during manufacture within a range 10º to 40º. The standard instrument has an acceptance angle of 20º, (as recommended by Commission Internationale de l´Eclairage, (C.I.E.), publication 88,1990). The luminance measurement range is 0 - 10,000 cd/m2, which can be scaled to suit customer requirements.

System components:

  • GEO-LUMIOS sensor
  • PC based utility software package for set - up and control of the instrument
  • Optional adjustable wall or post / pole mounting brackets
  • Optional wash - wipe facility