Mass, temperature, and relative humidity stability of automated sorption balances: results of an interlaboratory study

Automated sorption balances are widely used for characterizing the interaction of water vapor with hygroscopic materials. These instruments provide an efficient way to collect sorption isotherm data and kinetic data. A typical method for defining equilibrium after a step change in relative humidity (RH) is using a particular threshold value for the rate of change in mass with time. Recent studies indicate that commonly used threshold values yield substantial errors and that further measurements are needed at extended hold times as a basis to assess the accuracy of abbreviated equilibration criteria. However, the mass measurement accuracy at extended times depends on the operational stability of the instrument. Published data on the stability of automated sorption balances are rare. As a result, an interlaboratory study was undertaken to investigate equilibration criteria for automated sorption balances both by characterizing instrument operational stability and by measuring water vapor sorption in hygroscopic material specimens at extended times. This data publication contains mass, temperature, and RH stability records collected between March 2022 and October 2023 from 25 laboratories throughout the world.
Data were collected to better understand the operational stability of automated sorption balances.
For more information about this study and these data, see Zelinka et al. (2024).