Comparison of Mechanical Balance and Electronic Comparator Balance

摘要

The purpose of this study is to show the consistency of mass measurements from two different balances, the NRLM-2 mechanical balance and the AT1006 electronic comparator balance. In order to evaluate the uncertainty of the weighing results, some features of the balances are investigated. For the NRLM-2, the rest-point reading system is studied, and its uncertainty is evaluated to be 1 x 10~(-4) mg in mass. For the AT1006, a linearity error is measured at 500-mg intervals in the electrical weighing range from 0 to 10,000 mg by adding auxiliary weights to its support bracket. The results of these measurements suggest that the linearity error ranges from -7 to + 3 μ g. In addition it was found that the variation in the linearity error is less than 1 μg with a load difference of a few milligrams, suggesting that the linearity error is canceled out in substitution weighing with a mass difference of a few milligrams.