NO2: Classification of measured values
 | 0-5 µg/m³ |
 | 6-10 µg/m³ (10 µg/m³ = WHO guideline value) |
 | 11-20 µg/m³ (20 µg/m³ = limit value 2030 Directive) |
 | 21-40 µg/m³ (40 µg/m³ = limit value current Directive) |
 | >40 µg/m³ |
Classification of location type
 | rural background |
 | urban background |
 | close to traffic |
 | industrial |