Concentration
Concentration (ρ) = mass (m) ÷ volume (V) [g/cm³ = kg/dm³ = t/m³]
Statements concerning the concentration of chemicals must always go together with statements of temperature (ρ20 = concentration at 20°C).
Textile fibres absorb certain amounts of humidity depending on air moisture. For accurate determination of density it is therefore necessary to indicate the absorbed amount of moisture.
| fibrous material | concntration in kg/dm³ | |
| at 0% humidity | at 65% humidity | |
| Polyacrylonitrile (PAC) | 1,17 | 1,15 |
| Wool (Wo) | 1,30 | 1,31 |
| Silk (Ms) | 1,34 | 1,34 |
| Polyvinyl chloride (PVC) | 1,40 | 1,38 |
| Viscose (CV) | 1,52 | 1,49 |
| Cotton (Co) | 1,55 | 1,53 |
Source: SI - Systeme