600 Series – TunnelTech 601

The TunnelTech 601 Luminance photometer monitors the average luminance of a tunnel entrance and its surroundings. In accordance with Commission Internationale de l´Eclairage, (C.I.E.), publication 88, 1990 recommendations, the photometer monitors the average luminance within a 20 degree angle over a standard range of 0 – 6,500 cd/m2.
The detector is a metal/glass encased silicon diode photocell which is filtered to give a response that mimics the performance of the human eye. The detector is perfectly linear within its measuring range and has an instantaneous response to changing light levels.