ABSTRACT
This chapter offers the metrologist, bench scientist, and laboratory technician a practical guide to the determination of air density and the associated uncertainty estimate. In applying air buoyancy corrections to weighing, an equation to be used in calculating the density of air is required unless one makes a direct determination. The air density in a balance case was determined directly by Koch et al. using a simple device that enabled mass comparisons in air without the need to correct for air buoyancy. By a simple weighing of each of the two objects, the mass difference determination and the volume difference of the two weights were used to determine directly the density of the air in the balance case. The values of air density so determined could be compared to those calculated using an existing air density algorithm and measurements of barometric pressure, temperature, and relative humidity.
