● Low cost air quality measurement
● To determine the air quality,
based on a mixed gas sensor (VOC sensor)
● VOC = Volatile Organic Compounds
– Cigarette smoke
– Body odour
– Exhaled breathing air
– Carbon dioxide (CO2)
– Solvent vapours
– Emissions from building members and detergents
– Automobile exhaust gases
– Vapours of alkanoles
– Combustion smoke (from wood, paper, plastics)
– and many other gases
● 0-10 Vdc or 4-20 mA output (jumper selectable)
● QRT, standard version

● QRT S,
same as QRT
and with changeover contact

● QRT SL,
same as QRT
and with changeover contact
and with “traffic light” 5 coloured LED´s indication of air quality (VOC)

● QRT SLP,
same as QRT
and with changeover contact
and with “traffic light” 5 coloured LED´s indication of air quality (VOC)
and with Potentiometer

● QRT SS,
same as standard version QRT
but with stainless steel enclosure
for schools, military barracks and public buildings