Comparison of Methods for Estimating Mechanical Properties of Wood by NIR Spectroscopy

Table 7

Summary of modulus of rupture (MOR) based on radial and transverse face NIR spectra obtained using three different methods (Foss Direct, Foss Probe, and ASD Probe) for collecting spectral data. 334 samples were used to develop the calibrations.

Property/method	Number of factors	R^2	SEC	SECV	RPDc
Foss Direct
MOR (MPa)—radial face	4	0.69	8.4	8.6	1.7
MOR (MPa)—transverse face	6	0.73	7.9	8.0	1.9
Foss Probe
MOR (MPa)—radial face	7	0.50	10.6	11.2	1.3
MOR (MPa)—transverse face	10	0.61	9.3	10.3	1.4
ASD Probe
MOR (MPa)—radial face	8	0.67	8.6	9.2	1.6
MOR (MPa)—transverse face	5	0.64	9.0	9.2	1.6