Thermal conductivity common use in the construction and textile industries. The construction industry makes use of units such as the R-value (resistance) and the U-value (transmittance). Although related to the thermal conductivity of a material used in an insulation product, R- and U-values are dependent on the thickness of the product. Likewise the textile industry has several units including the tog and the clo which express thermal resistance of a material in a way analogous to the R-values used in the construction industry. There are a number of ways to measure thermal conductivity. Each of these is suitable for a limited range
Air Quality Egg different versions; depending on what customers choose, the egg can measure Particulates (PM10, PM2.5 and PM1.0), CO2, NO2, SO2, ozone, carbon monoxide and/or Volatile Organic Compounds. The Particulate version detects particles as small as 0.3µm (microns), using two Plantower PMS5003 sensors. The PM2.5 measurements of the Air Quality Egg version 2 had an R² correlation factor of 0.79 to 0.85 with a professional reference sensor, in a field test run by the Sout Coast Air Quality Management District (an R² approaching the value of 1 reflects a near perfect correlation, whereas a value of 0 indicates a complete lack of