What does a TVOC meter measure?
A Volatile Organic Compound meter or VOC sensor is used to test air for contaminants and to measure air quality. VOCs are a large group of chemicals that are found in many products we use to build and maintain our houses. VOCs evaporate from substances such as cleaning products, adhesives, paints, new carpets, copiers and printers to building materials and furnishings. A VOC sensor directly measures ambient concentrations of these chemicals associated with bad air quality. The most common compounds of these gases are benzene, ethylene glycol, formaldehyde, methylene chloride, tetrachloroethylene, toluene, xylene, and 1,3-butadiene.
How do VOCs affect human health?
VOCs have a negative impact on human health. They are known to cause eye, nose and throat irritations, headache, drowsiness, dizziness, nausea, difficulty concentrating and fatigue. Higher concentrations may cause irritation of the lungs, as well as damage to the liver, kidney, or central nervous system. Therefore, it is important to monitor the VOC levels and to extract the contaminated air from the area. The best way to remove VOC's from indoor air is to increase ventilation and to supply more fresh air.
What is the difference between VOC and TVOC?
For a more accurate indication of the indoor air quality, Sentera developed TVOC sensors that can monitor temperature, relative humidity, ambient light and VOC levels. TVOC or Total Volatile Organic Compounds correspond to the sum of the different VOCs in an air sample. TVOC gives a more correct picture of the air quality, since it does not measure a single compound, but the sum of all individual VOCs.
Among many VOCs, the TVOC sensors have an increased selectivity to hydrogen or H2. In indoor environments, the H2 concentration is expected to correlate well with the CO2 concentrations as human breath contains significant concentrations of both CO2 (4 %) and H2 (10 ppm). Furthermore, humans are the major source of CO2 and H2 in typical indoor environments. This makes it possible to distinguish the influence of human presence from other contaminants and control the ventilation system based on occupation of a space.