NIST researchers are developing ultra-sensitive mass measurement techniques to improve the dissemination of the kilogram. They are examining microscopic processes affecting mass changes in physical artifacts used for mass dissemination.
Two types of oscillators are being used: double paddle oscillators (DPOs) and quartz crystal microbalances (QCMs). The DPO has a large surface area and high quality factor at low temperatures, while the QCM is widely used in science and industry.
The researchers are growing solid phase films at low temperatures and monitoring mass loss through sublimation or evaporation. They are also comparing QCM measurements to SI-calibrated masses to assess accuracy.
The absolute mass reported by the QCM is accurate to about 1%, limited by area determination. This work aims to improve mass dissemination and fundamental thermodynamics data on enthalpies of sublimation.
Source: https://www.nist.gov/programs-projects/quantifying-environmental-contributions-mass-change
Keywords: Metrology, Resonators, Mass measurement, Enthalpy, Thermodynamics
