Study on the Mesopic Vision Theory Used in Road Tunnel Lighting Measurement

The highway tunnel lighting level is usually under mesopic vision condition. But the traditional luminance and illuminance test instruments of road lighting are corrected by photopic vision spectral luminous efficiency. Because of the correction error, the test results can't express the true feeling of human eyes. And this case is particularly serious when measuring the road lighting with different lighting sources. In this paper, the emission spectrum distributions of high-pressure sodium lamp(HPS) and white LEDs are deeply studied based on mesopic vision luminous efficiency model. And research results contains the methods of the secondary correction, which can be used in measuring the road lighting by traditional corrected instruments. The conclusion is beneficial to obtain more accurate highway tunnel lighting values, and give an innovative method for the analysis of lighting sources performances.