抄録
A changes with passage of time of calibration weights affect uncertainty of measurement on mass standards and balances. Specially, interval of calibration for mass standards needs to estimate its change with passage of time. We have verified the change with passage of time for our mass standards, 1 mg-200g, three times in the past; February 1996, April 1999 and November 2001. So, this paper introduces its detailed analysis with measuring uncertainty.
