Abstract
In recent times, there has been an increasing need to establish the traceability for most measurements. When the traceability of the measurement is established, it is necessary that measurement uncertainties are evaluated at every level of calibration. Measurement uncertainty represents the quantitative indication of the quality of the measurement result. The method for evaluating and expressing uncertainty is common throughout the world and measurand. In this study, we represented the sources of the uncertainty in the rice moisture content measured by the drying method, and the method used to evaluate a particular source of uncertainty. Then, we evaluated the uncertainty in the polished rice moisture content measured by the drying method. As a result, the moisture content of the polished rice measured by the drying method is represented by X=13.96%±0.13%, where the number following the symbol ± denotes the numerical value of an expanded uncertainty. The first major source of uncertainty was the deviation between the same types of grinders. The standard uncertainty between the grinders was 0.064%. On the other hand, the uncertainty in the mass measurements was sufficiently smaller than the expanded uncertainty. The standard uncertainty in the mass measurement was 0.005%. It can be stated that the expanded uncertainty will not be affected by the uncertainty in the mass measurements. From these results, it was possible to assign a numerical index of how precise the grain moisture measurement is as measured by the drying method. Also, because it is now possible to assign uncertainty for grains to calibrate grain moisture meters, this has opened the way for establishing traceability of grain moisture meters.
