The Archimedes' Resonant Mass Measurement technique measures a particle’s buoyant mass which can be used to calculate its mass and size. This requires a value for the density of the particle being measured, as well as the density of the fluid in which it is suspended, to be known. The density of a particle can be obtained using the Archimedes instrument even if its size is unknown. This is done by measuring the buoyant mass of the particle in different fluids of varying densities. This method has been shown to be very effective at accurately measuring lower density particles such as latex. Measuring particle density allows for the accurate calculation of mass and size and can give structural information for particles which are composed of more than one material.