This paper presents a hydrostatic weighing apparatus (HWA) for the density determination of weights in the range of 2 kg to 10 kg including 1 kg. The measurement is based on Archimedes’ principle by using 1 kg sphere as a solid density standard to determine the density of the reference liquid. The HWA consists of a precision balance, a immersion pan, reference weights, a weight carrier, a sample carrier, a reference liquid, a thermostat, and a controller for stepping motors. The reference weights with capacity of 1 kg, 2 kg, 2 kg, 5, kg, and 10 kg are designed and installed to be weighed at the bottom of balance. The measurement uncertainty of density of weights are evaluated as preliminary test of newly designed and fabricated equipment.

For the dissemination of this quantity torque standard systems are normally operated manually, originating high consumption of man-hours in the development of a calibration. This work presents the control and characterization of a Torque Transfer Calibration System and the benefits of the automatic control system.

For the dynamic calibration of torque transducers, a calibration device has been developed. This paper describes the model of the measuring device and methods for the determination of its model parameters. The modelling of the calibration set-up is required for the identification of the corresponding model parameters of the torque transducer under test. These parameters describe the transducer's dynamic behaviour. Measurement methods and devices for the determination of mass moment of inertia and torsional stiffness are explained. This research is part of EMRP JRP IND09 - "Traceable Dynamic Measurement of Mechanical Quantities".

A 10 N·m dead weight torque standard machine (10- N·m-DWTSM) has been developed and evaluated since 2006. The main parts of the moment arm in the 10-N·m-DWTSM are made of low thermal-expansion alloy (Super Invar). It is known that parts made of Super Invar vary in length with age. In this study, the moment arm length was recalibrated using a 3D coordinate measurement machine. As a result, the moment arm length was found to have lengthened by an average of 6.3 µm in five years. Also, the relative expanded uncertainty of torque, W_tsm, realized by the 10-N·m-DWTSM was revaluated in a range from 0.1 N·m to 10 N·m, and W_tsm was 7.0 × 10^-5, with the coverage factor k being equal to 2. In addition, the 10-N·m-DWTSM was compared with the 1-kN·m-DWTSM at NMIJ/AIST by using torque measuring devices after estimating W_tsm realized by the 10-N·m-DWTSM. Equivalence between the two DWTSMs was confirmed within the uncertainty of comparison.

The adsorption layers on the surface of silicon artifact have been determined experimentally as a function of relative air humidity in the range of 0.07 < h < 0.73 using gravimetric method. For the purpose of this work 1 kg silicon sorption artifacts were fabricated, which have same surface finish, material properties but with very different surface area of 507.8 cm2. In this experiment ultra precision mass comparator and special humidity control unit were used. The adsorption isotherm of water vapor on the silicon surface with R_z < 26.6 nm measured and sorption behavior of silicon surface is being type II by BET classification, BET parameters µ_m = 0.017 µg/cm², c_B = 9.3 were found. The coefficient of water vapor adsorption in moist air was δµ/δh = 65.3 ng cm^-2 %^-1 in the limited humidity range of 0.3 < h < 0.6.