Volatile Organic Compounds The doser system marks the supply-air of the room with a known amount of tracer-gas such as Sulphur Hexa Flouride, Freon 134a, Freon 152 or Nitrous Oxide. Measurements of Indoor Air Quality is an important application for detection of Carbon Dioxide, Carbon Monooxide and Volatile Organic Compounds. in Public bookmarkswith compoundsorganicvolatile