Laboratory of primary mass metrology continue work on dissemination of mass unit using measurements under non ambient conditions using vacuum mass comparator. Method presented in this paper allows determination of mass and volume of weights in range 100 g – 1 kg with separate mass and volume standards.

The article discusses basics of procedure for the calibration of automatic gravimetric filling instruments. It deals with the definition of the model function of measurement procedure, determination of the reference mass of test fills and estimation of measurement uncertainty. Depending on whether the calibrated instrument is able or not to record its results and on this basis adjust the filling process, two options for the selection of the calibration model function are addressed. Contributions to the measurement uncertainty are presented with an emphasis on the differences arising from the application of one or another model function.

Through the analysis of the working principle of the original control system in deadweight force standard machine with independent weight application structure and the stress state of the center boom, we find out the inherent problem in proceeding test, which contains returning process, or in the returning test, which contains proceeding process, due to the weight rearrangement in loading and unloading process. To solve this problem, we propose an innovative technical improvement solution based on classical structured deadweight force standard machine. The standard measurement instrument of force value dissemination is employed to measure the force value volatility caused by weight rearrangement in classical structured deadweight force standard machine.

The build-up force standard machine is widely used in large scale force measurement. The force measurement range of the standard machine depends on a reference force transducer, and it is usually from 10% to 100% rated force in a measurement process. In order to perform continuous calibrations, it should be avoided two measurement processes by changing reference force transducer. This paper describes a new type of wide range standard machine, which is based on exchanging two reference force transducers in operation process. It can measure up to 10 MN, and its range is extended from 3% to 100% rated force in one measurement process. In addition, the repeatability and the relative reproducibility error with rotation of the new machine are calculated.

We present the current mathematical procedures at METAS for disseminating the kilogram. We compare the classical method for solving a linear system of equations of mass comparisons to the Lagrange multiplier method. In addition, we have studied the influence of redundancy in mass comparisons and found that the combined standard uncertainty can be reduced when using a redundant design matrix.