Surface analytical model and sorption artifact designing method


  • Xiaoping Ren National Institute of Metrology
  • Jian Wang
  • Ombati Wilson
  • Yong Wang
  • Bai-fan Chen
  • Chang-qing Cai



Mass standards with alternative shapes are difficult to design due to the number of complex parameters. An analytical model based on surface sorption experiments is presented to study adsorption. This model is based on an optimization algorithm that is conceptualized to help to design the best sorption artefacts. Experimental artefacts, cylinder-weight and stack-weight, were of the same volume but different surface areas. This algorithm in essence determines the optimum surface of the artefact. After machining the artefact, surface sorption measurements were carried out. A sorption experiment was done by transferring the artefact from air to a vacuum. Then the surface sorption model was set up which represented the relationship between sorption coefficient, time t and relative humidity h. Logarithmic models were used to fit the variation of sorption coefficient per relative humidity h with time t.






Research Papers