This technique consists in taking measurements at the source of air emissions and/or sampling with Tedlar bags or Dräger tubes and transferring the samples to the laboratory for treatment and analysis. The group has two laboratories equipped with advanced analytical techniques that give it a wide analytical capacity. Among the techniques available are the following: Total organic carbon (TOC) analyser in air with flame ionisation detector (FID); Photoionisation detector for measuring volatile organic compounds; Gas chromatograph equipped with a capillary column that allows the composition to be determined in organic compounds such as ethanol, isopropanol, styrene, xylene, toluene, butyl acetate, etc. Manual air temperature and humidity measuring equipment; carbon dioxide (CO2) analyser; gasometer for measuring air flow; digital manometer with a pressure sensor for measuring pressure losses; biogas analyser.