How a pycnometer works
When you fill the body with distilled water and insert a capillary tube, the water rises to the top of the capillary tube and fills it. This allows the same volume of water to be added at all times.
Weigh the density of solids
1)Weigh the mass (WP) of the solid in a dry pycnometer.
2)Water is added to about 80% of the above pycnometer, and the pores of the solid are degassed in a boiling water bath or a vacuum bottle.
3)After the pycnometer has returned to room temperature, fill the pycnometer with water.
4)Weigh the mass (WPW) by inserting a capillary tube.