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4.1 Advanced Mass Measurements
Carroll Croarkin
Georgia Harris A 5-day workshop on mass measurements was given at NIST in March 1999 for industrial and state metrologists, weight manufacturers and balance manufacturers. Participants take two lower level courses before registering for this workshop which, in large part, focuses on statistical methods for controlling mass measurement processes and assessing uncertainties of mass determinations. Attendees were introduced to concepts of: theory and solution of weighing designs; error analysis; components of variance; and procedures for controlling measurement processes. Specific applications to mass measurements included:weighing designs for common weight sets; propagation of uncertainties through several series of designs; computations of uncertainty from check standard measurements; control of balance precision; and computation of total uncertainties. Course materials were supplemented by interactive computerized workshops which strengthen skills in the areas of weighing designs and process control, and this year, for the first time, attendees were instructed in the use of pages in the NIST/SEMATECH Engineering Statistics Handbook that relate to mass calibrations.
Figure 20: A detail from the Handbook showing three series for calibrating a 5,3,2,1 weight set starting with 2 reference kilograms
Date created: 7/20/2001 |