1 General Provisions 1 2 Terms and Symbols 4 2. 1 Terms 4 2. 2 Symbols 5 3 General 7 4 Lighting of Threshold Zone 16 4. 1 Luminance of threshold zone 16 4. 2 Adaptation luminance 18 4. 3 Length of threshold zone 20 5 Lighting of Transition Zone 22 6 Lighting of Interior Zone 25 6. 1 Luminance of interior zone 25 6. 2 Luminaires' layout of interior zone 26 6. 3 Lighting of lay-by and horizontal adit 28 7 Lighting of Exit Zone 30 8 Emergency Lighting and Approach Lighting 31 8. 1 Emergency lighting 31 8. 2 Approach lighting 31 9 Energy-conservation Standards and Measures 33 9. 1 General 33 9. 2 Energy-conservation standard 34 9. 3 Energy-conservation measures 35 10 Lighting Calculation 40 10. 1 General 40 10. 2 Illuminance calculation 41