tiheysmitta

Tiheysmitta is the measurement of density, the mass per unit volume of a material or substance. It encompasses absolute density, usually expressed as mass per volume (for example kg/m^3 or g/cm^3), and related concepts such as bulk density and true density. Density is influenced by composition, structure, temperature and pressure, and it is a key parameter in quality control, material selection, and buoyancy calculations.

For liquids, density is commonly determined by direct volume and mass measurements or with dedicated density meters. Methods include gravimetric approaches, using precise balances and calibrated volumes, and oscillating-tube or buoyancy-based densitometers. Temperature control is essential because density changes with temperature. For solids, density can be found by measuring mass in air and in a calibrated immersion fluid (Archimedes principle), or by using a pycnometer to determine the volume of a fixed sample. Gas pycnometry provides true density by measuring volume with a known gas before and after sample immersion. For powders, bulk density and true density can be distinguished, often requiring specialized apparatus to account for porosity and compaction.

Instruments used include densitometers, hydrometers, pycnometers, and gas pycnometers. Standards and procedures exist across ISO and ASTM families to ensure comparability of results for plastics, metals, ceramics, foods, and pharmaceuticals. Density measurements are routinely used to verify material specifications, to assess purity and porosity, to correct for temperature effects, and to support calculations related to buoyancy, mixing, and processing.