Glossary
Density
The mass density is defined as the ratio between mass and volume.
The volume is generally a function of the temperature and pressure. Mass changes are relatively small compared to the volume effects and can be observed in TGA or STA runs. Density is a material property; in the context of thermal analysis, it is examined as a function of temperature.
Using special software, density changes can be calculated for solid and liquid samples and for the transition from the solid to the liquid state (e.g., melting of a metal sample; see example below); these calculations are based on the thermal expansion, which is measured via dilatometry.
![](https://analyzing-testing.netzsch.com/_Resources/Persistent/4/d/6/b/4d6b557e9f00754a0aa4f2578d626173d57c672e/density-600x390.webp)
![](https://analyzing-testing.netzsch.com/_Resources/Persistent/8/1/0/7/81071b5f6fe86b53f85b55b97a2222d6d296e75f/web_AdobeStock_296563182-1277x719-1277x719.webp)