The Wireless Tunnel Air Quality Sensor combines air particle counting with volatile organic compounds, temperature and humidity in a single sensor.

Air Particle Count

Used to monitor the amount of dust particles in the air.
Detection of 5 different particle sizes from PM0.5 to PM10.
Air particle sensors are utilized during indoor air quality (IAQ) assessments for clean rooms and workplaces. The specific type of particles is not detected, but it identifies the quantity or mass of airborne particles. These air particles could be sourced from :

Exhaust smoke

Airborne dust particles

Pollen

Volatile Organic Compounds

The sensor detects but does not differentiate between, various Metal Oxide (MOx) gases, displaying the value as a VOC Index.
Examples of these gases are :

Acetone (eg. paints and glues)

Toluene (eg. furniture)

Ethanol (eg. perfume, cleaning fluids)

Hydrogen Sulfide (eg. decaying food)

Benzene (eg. Cigarette smoke)

The VOC Index is a logarithmic scale that is relative to the typical indoor gas composition over the past 24 hours. With a range of 0 to 500, the typical value for a normal environment being 100. Values greater than 100 indicate worsening air quality with a higher concentration of metal oxide gases over the past 24 hours. Values lower than 100 indicate improving air quality.