The Accuracy in Microweighing in Vacuum and Controlled Environments

Accurate weighing depends on both physical factors and the weighing technique. There are two categories of physical factors: the location and support of the balance, and physical phenomena. Important such phenomena include processes of heat transfer by convection and radiation in rarefriction gases, Archimedes buoyancy, electrostatic, magnetostatic and gravitational effects, etc. Surveys of disturbances which affect the accuracy of weighing in vacuum or in controlled environments have been published elsewhere. This paper describes a high-vacuum apparatus connected to a Cahn RG ultramicrobalance. The system was adapted for investigations of long-time kinetic runs of oxygen loss in oxide superconductors in dynamic vacuum, and of other gas - solid interactions. Typical calibration curves for 'not fully compensated system' are presented in controlled environments at cryogenic temperatures. This revised version was published online in July 2006 with corrections to the Cover Date.