Having invested in an extra air purifier not needed so far this season, but the swidden burning in Golden Triangle, Burma and Laos will no doubt visit as last year.
Chez Rubba brekkie today 29 Feb here 60 miles n of c rai, My low tech gizmo was c700 baht off Shopee or Lazada, can be hand held outside or dispaly stand, powere by c cable same as my phone, the temp is accurate o far, if anyone intereted I'll earch my purchae once eye better
HCHO is the molecular formula for formaldehyde, also known as methanal. Formaldehyde is a colorless, pungent gas with a characteristic odor. It is the simplest of the aldehydes and is used in many chemical manufacturing processes
TVOC (volatile organic compounds) levels can be measured in milligrams per cubic meter (mg/m3), parts per million (ppm), or parts per billion (ppb).
The concentration of carbon dioxide in the Earth's atmosphere is currently nearly 412 ppm and rising. This is a 47% increase since the beginning of the Industrial Age, when the concentration was near 280 ppm.
Indoor concentrations of carbon dioxide are always higher than outdoor levels due to lack of ventilation and high insulation. The UK government says that over 1500 ppm indicates poor ventilation. ASHRAE says that under 1000 ppm indicates good indoor air quality.
According to Quora, 600 ppm is considered the limit for acceptable levels. Between 600 and 1000 ppm, people begin to complain of “stuffiness” and odors. Between 1000 and 2500 ppm, drowsiness starts to occur. Between 2500 and 5000 ppm you start to see adverse health effects.