Reference Values for the Sensitivity of Standard Accelerometers Used in Intercomparisons
David J. Evans, Stefan D. Leigh, Beverly F. Payne
The National Metrology Institutes (NMIs) of 5 countries in North America and South America participated in an interlaboratory comparison involving the calibration of the magnitude of the sensitivity of 3 standard accelerometers. This comparison was performed by laboratories within the framework of the Interamerican Metrology System (SIM). One of the key values to be obtained in any interlaboratory comparison is an estimate of the reference values for the artifact being calibrated. Three statistical methods have been used to obtain candidate reference values and associated uncertainties from the SIM intercomparison data: an average of means method; a method based on the ISO Guide to the expression of uncertainty in measurement; and a maximum likelihood method. Reference values and associated uncertainties obtained using the three methods are presented and compared, as well as useful graphical displays with resulting qualitative conclusions.