1. A small glass vessel with a stopper, used in laboratories to measure the density or specific gravity of liquids or solids.
Usage: technical; also called a specific gravity bottle or density bottle

Examples

• The chemist used a pycnometer to determine the density of the unknown liquid.
• A pycnometer must be carefully calibrated before measuring the specific gravity of a sample.
• The laboratory was equipped with several pycnometers of different sizes for various experiments.
• To find the density, the student filled the pycnometer with the liquid and weighed it on a balance.
• Pycnometers are essential tools in materials science for characterizing the properties of substances.