Fig. 4From: Applicability of effective medium theory to wood density measurements using terahertz time-domain spectroscopyRelations of a relative permittivity, ε′, and b dielectric loss, ε″, along the longitudinal axis to the density, ρ 0, of oven-dry wood at a frequency of 0.6 THz. The plot symbols are the same as in Fig. 2 Back to article page