gravimetrically

The mass of each size fraction is determined gravimetrically.

The quantitative determination of phases is often determined gravimetrically.

Historically, the quantity of palladium in a sample may be determined gravimetrically by precipitation as palladium(II) iodide.

The armament of the Windstar consists of three gravimetrically enhanced neutron particle beam cannons, similar to those found on a Sharlin Class Warcruiser.

On a side note, when intending to measure certain quantities of water at temperatures other than "room temperature" ( 20-25 C); we often measure the quantity of water "gravimetrically" or by weighing the water.