Developing the NIS solid density hydrostatic weighing system up to 20 kg
National Institute of Standards, Mass, Density and Pressure Laboratory, Giza, Egypt
2 Al-Azhar University, Faculty of Engineering, Department of Mechanical Engineering, Cairo, Egypt
3 National Institute of Standards, Force & Material Metrology Laboratory, Giza, Egypt
* Corresponding author: firstname.lastname@example.org
Accepted: 24 September 2020
This paper presents a developed design and construction to improve the performance and increasing the density measuring capability of the previous Hydrostatic Weighing Apparatus (HWA-NIS) at the National Institute of Standards (NIS) up to 20 kg. The previous (HWA-NIS) has been constructed up to 10 kg on 2014. The 2-Positions mass handler in the previous (HWA) was developed with 4-Positions pentagon shape to be able to make handling for individual masses in a group at once, when transferring the traceability from the primary standard “the Silicon Sphere” to the standard masses in the density scale weighing process. The weighing pan in the previous (HWA) was developed with four suspension wires with a diameter of 0.3 mm each, leads to reduce the surface tension affect on the measurement uncertainty by factor four times. The density of the standard masses in the range from 2 kg up to 20 kg were measured with an improved expanded uncertainty from 0.150 kg/m3 to 0.078 kg/m3 respectively due to reducing the effect of surface tension via the developed design of the weighing pan.
Key words: Mass metrology / masses / volume and density / hydrostatic weighing apparatus / solid density uncertainty
© M. Hamdy et al., published by EDP Sciences, 2020
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.