Abstract:

To affirm the reliability of testing result, the direct evaluation method was used to evaluate the uncertainty of fat and oil content of feather and down in this paper. The repeatability of sample measurement, sample weighing, fat and oil weighing were proved to be the main sources of uncertainty of fat and oil content by analysing the principle of measurement of fat and oil content. All components were evaluated respectively. The combined standard uncertainty and the expanded uncertainty were calculated by combining all the components of uncertainty. The analysis result shows that the uncertainty from weighing flasks is the prime factor while weighing flasks by the balance of 1 mg resolution which causes the higher uncertainty, and that the uncertainty from the repeatability of sample measurement and fat and oil weighing are the most important factors for the measurement uncertainty of fat and oil content when weighing the flasks by the balance of 0.1 mg resolution.