When can air buoyancy corrections for mass calibration generally be ignored?

Air buoyancy corrections for mass calibration can generally be ignored when the standard and the unknown are made of the same material. This is because buoyancy effects, which arise from the displacement of air, depend on the volume and density of the objects being weighed. When both objects are made from the same material, their densities and the corresponding buoyant forces acting on them will be equal. As a result, the correction cancels out when both the standard and unknown have similar buoyancy effects, leading to negligible impact on the measurement.

In scenarios involving different materials or when heavy items are weighed, the buoyancy effect can have a substantial influence on the measured mass, requiring careful compensation for accurate results. Other factors, such as the environment in which the calibration is performed or the type of measuring equipment used, can be important but may not render the buoyancy correction unnecessary as effectively as the material similarity does.