Determining density for a variety of solids and liquids
We undertake research in a wide range of areas associated with density determination for solids, powders and liquids to support the requirements of UK industry.
Density determination can be used in additive manufacturing both as an assessment of the quality of feed material and to determine the integrity and reproducibility of the fabricated components. Gas pycnometry using helium has the potential to provide a quick and easy way of making these measurements and NPL is carrying out research to improve the traceability and repeatability of such measurements.
Density of powders
NPL has developed methods and equipment to determine the density of powders and particulates using gas and liquid pycnometric techniques with traceability to the SI via the density of single crystal silicon. By using the techniques together, assessment of the surface porosity and wettability of powders can also be made. We are undertaking a programme of continuous improvement to expand the areas of application and improve the accuracy of these measurements.
NPL pioneered work on weighing in vacuum which has allowed us to make highly-accurate determinations of the densities of porous materials, such as concrete, which are unsuitable for measurement by conventional liquid immersion methods.
NPL has worked with density meter manufacturers to develop standards and test methods to assess and improve the performance of density meters. We are also looking into ways to satisfy emerging requirements, for example in the characterisation of biofuels and for real-time on-line measurements of hydrocarbons and consumables.
Find out more about NPL's Measuring density service
Find out more about NPL's Technical consultancy service
Find out more about NPL's Manufacture and supply of transducers service