Where:
mcor = PM mass corrected for buoyancy.
muncor = PM mass uncorrected for buoyancy.
[RHO]air = density of air in balance environment.
[RHO]weight = density of calibration weight used to span balance.
[RHO]media = density of PM sample media, such as a filter.
Where:
pabs = absolute pressure in balance environment.
Mmix = molar mass of air in balance environment.
R = molar gas constant.
Tamb = absolute ambient temperature of balance environment.
40 C.F.R. §1065.690