Determination of Density
Weighting of mass + Volume measurement
VOlume measurement based on overflow vessel
Problem: Natural wood takes up water
Electro-magnetic radiation (X-rays)
CT of spruce knots
Bulk Density
p = m/V = Masse/Volumen at moisture content u
Oven-dry density
p=m/V = mass/Volume of oven-dry wood
Raumdichtezahl
R=m/V = mass of oven dry wood/volume of maximum swollen wood
Cell wall density
pr= m/V = mass of oven dry wood/cell wall volume
Variability of density among wood species
Factors: species, origin, climate, position
Variability of density between wood species
Effect on growth ring width on oven-dry density
Softwoods: Higher growth ring width —> lower density
Diffuse-porous: no influence
RIng-porous: Higher growth ring width —> higher density
Density distribution in a growth ring
Earlywood: lower density
Latewood: higher density
Density compared to distance from the bark
The higher the distance from the bark the lower the density
Correlation between stem height and density
No correlation
Density of Juvenile and Adult Wood
Juvenile wood (innen): lower density due to higher MFA
Adult wood (aussen): higher density
Density of compression wood
Higher than density of normal wood
Last changeda year ago
