The evaluation of the measurement uncertainty of the thousand-seed weight in accredited testing laboratories

The evaluation of the measurement uncertainty of the seed quality indicators is an integral part of testing in accredited testing laboratories. The thousand-seed weight is one of the essential indicators, the limit values of which are not standardized, but are taken into account when determining the cost of a lot of seeds or seeding rates. The developed method for evaluating the measurement uncertainty of the thousand-seed weight by measuring two weights of 500 seeds is presented in the paper. According to the analysis of a basic calculation formula, the impact of correctness and accuracy on the measurement uncertainty was assessed. It was shown that the major measurement uncertainty components are uncertainties of weighting and repeatability. The repeatability is advisable to be evaluated by Type В using the limit of repeatability, if the national standard specifies the testing method. The authors have analysed the conditions when other components can be neglected. The uncertainty budget and an example of its calculation were received.