Visibility (K-value), NO, NO2, NOx, CO, Temperature
K-value: 0 ... 15 km⁻¹ / 0 ... 200 km⁻¹
NO: 0 ... 20 ppm / 0 ... 45 ppm
NO2: 0 ... 1 ppm / 0 ... 5 ppm
CO: 0 ... 100 ppm / 0 ... 300 ppm
Temperature: -25 ... +55 °C / -25 ... +75 °C
ASTRA "Guideline - Ventilation of Road Tunnels" (2008)
RABT 2006
RVS 09.02.22