Tunnel Photometer Model TLS-420

The Hagner TLS-420 Tunnel Entrance Photometer is designed to measure the average luminance of road tunnel entrance and its surroundings according to CIE recommendations and is used, together with a PLC/computer, to regulate the lighting inside the tunnel. The idea is to control the illumination inside the tunnel to a level corresponding to the degree of light adaptation of an approaching cardriver´s eyes.
Prices on request.
Introduction
The aim of road tunnel lighting is to ensure that traffic, both during daytime and nighttime, can approach, pass through and leave a tunnel, at the designated speed, with a degree of safety and comfort not less than along the adjacent stretches of open road.