Notes on conversion:
1 - To convert ppm or ppb to µg/m³ in 1 atm and 25°C (used in code)
The equation to convert ppm to µg/m³ for a Z ppm concentration of a given element/compost is:
C = 40.9 * Z * molecular_weight (µg/m³)
for a M ppb concentration:
C = 0.0409 * M * molecular_weight (µg/m³)
where:
C: is the equivalent ppm value in µg/m³.
Z: is the ppm concentration of a given
element/compost.
M: is the ppb concentration of a given
element/compost.
molecular_weight: is the molecular weight of the element/compost in gram/mole.
2 - To convert ppm or ppb to µg/m³ in some known pressure (X in atm) and temperature (Y in Kelvin)
The equation to convert ppm to µg/m³ for a Z ppm concentration of a given element/compost is:
C = 12.195 * Z * (X/Y) * molecular_weight (µg/m³)
for a M ppb concentration (ppm value = ppb value / 1000):
C = 0.012195 * M * (X/Y) * molecular_weight (µg/m³)
where:
C: is the equivalent ppm value in µg/m³.
Z: is the ppm concentration of a given
element/compost.
M: is the ppb concentration of a given
element/compost.
molecular_weight: is the molecular weight of the element/compost in gram/mole.
X: is the current atmosphere pressure in atm.
Y: is the current temperature value in Kelvin.