Parameters:
(1) air temperature in °C
(2) dew point temperature in °C
(3) barometric pressure in mm Hg
density in g/L =
= 1.2047 * 273.13 / (°C + 273.13) * ((barometric pressure) - (0.3783 * (water vapor pressure in mm))) / 760
water vapor pressure from -40 to -5°C =
= (0.000076 * ((dew point temperature)^3)) + (0.008186 * ((dew point temperature)^2)) + (0.3126 * (dew point temperature)) + 4.367
water vapor pressure from -5 to +25°C =
= (0.000338 * ((dew point temperature)^3)) + (0.008436 * ((dew point temperature)^2)) + (0.3458 * (dew point temperature)) + 4.563
water vapor pressure from +25°C to + 60°C =
= (0.000946 * ((dew point temperature)^3)) - (0.04443 * ((dew point temperature)^2)) + (1.95 * (dew point temperature)) - 12.13
