Success in using near infrared spectroscopy to estimate wood properties of Pinus taeda radial strips not due to autocorrelation (original) (raw)

Determination of radial profiles of wood properties using a near infrared scanning system

Journal of Near Infrared Spectroscopy, 2020

A near infrared (NIR) spectrometer, equipped with a 2-mm diameter fiber optic probe, was used to develop a rapid and automated method for determining the radial profiles of wood properties for six tree species of the boreal forest of eastern Canada. Partial least squares regressions were performed using individual spectra, collected every 5 mm, from the pith to the bark, using 1,538 samples previously scanned by SilviScan to provide reference data. Results obtained for density (r2 of 0.57 to 0.65; SE of 21 to 33 kg/m3), microfibril angle (0.56 to 0.82, 2.3 to 4.8°) and modulus of elasticity (0.71 to 0.85, 1.3 to 1.8 GPa) were suitable for the purpose of this study. This method was then applied to more than 30,000 tree cores and the resulting radial profiles of the properties were consistent with literature. Area-weighted average predictions also gave reliable estimates at the disk scale. NIR-estimated values were strongly correlated to the measured density (r of 0.83 to 0.93) and mo...

Challenges in the use of Near Infrared Spectroscopy for improving wood quality: A review

Forest Systems

Aims of study: Forestry-related companies require quality monitoring methods capable to pass a large number of samples. This review paper is dealing with the utilization of near infrared (NIR) technique for wood analysis.Area of study: We have a global point of view for NIR applications and characterization of different kind of wood species is considered.Material and methods: NIR spectroscopy is a fast, non-destructive technique, applicable to any biological material, demanding little or no sample preparation. NIR spectroscopy and multivariate analysis serve well in laboratories where the conditions are controlled. The main challenges to NIR spectroscopy technique in field conditions are moisture content and portability.Results: In this review, the methods and challenges for successfully applying NIR spectroscopy in the field of wood characterization are presented. Portable equipment need to record NIR spectra with low noise and low sensitivity to temperature and humidity variations...

Assessing Trees, Wood and Derived Products with near Infrared Spectroscopy: Hints and Tips

Journal of Near Infrared Spectroscopy, 2016

Wood is a renewable and valuable resource for a variety of end-use application areas. However, rapid and reliable assessments are needed to identify the quality of the tree, timber or wood product at all stages of production and processing. The ideal technology for assessing wood and wood products must provide reliable data, be user-friendly, cost-competitive and provide a rapid analysis. The ultimate application of near infrared (NIR) spectroscopy of wood or wood products is to substitute for costly and time-consuming reference measurements in order to aid process optimisation or determine properties and genetic traits on large numbers of individual samples. Increased interest in the application of NIR spectroscopy in various research fields including wood is observed nowadays. A vast number of publications highlight the potential of NIR spectroscopy for the characterisation of wood in a broad area of uses. The Journal of Near Infrared Spectroscopy has published two special issues ...

Near Infrared Spectroscopy for Estimating Wood Basic Density

Cerne, Lavras, 2009

ABSTRACT: Wood basic density is indicative of several other wood properties and is considered as a key feature for many industrial applications. Near infrared spectroscopy (NIRS) is a fast, efficient technique that is capable of estimating that property. However, it should be ...

Near Infrared Spectroscopy ( NIRS ) as a Tool for Effective Classification of Wood

2008

Wood from different tree species is commonly similar in visual appearance but still have considerable differences in machining and wood properties. Even heartwood and sapwood from the same tree species may be difficult to separate visually, but the wood properties important for the quality of the final products may differ. Hence, within the forest products industry there is a great need to non-destructively evaluate wood quality prior to and during manufacturing in order to ensure effective allocation of raw material, and to obtain consistent and well defined quality of the end products. Near infrared spectroscopy is a promising technique because it requires minimal, if any, sample preparation and provides results rapidly, even when used on intact, opaque biological samples. In this paper we use near infrared spectroscopy combined with multivariate statistical analyses for classification of wood types. Case I considers heartwood and sapwood from Scots pine. On freshly cut wood heart...

Rapid Prediction of Basic Wood Properties by Near Infrared Spectroscopy*

2006

The optimal utilisation of a wood raw material is dependent on the wood properties. In this study near infrared (NIR) spectroscopy was used to nondestructively predict density, modulus of elasticity, and modulus of rupture for small clear specimens cut from Picea abies (L.) Karst. (Norway spruce) trees. NIR spectra were recorded directly on the wood surface of each specimen as close as possible to the fracture developed during the bending test. Models were calibrated using partial least squares regression. The validation method was test set validation by data splitting. The correlation between predicted and measured values was highest for modulus of elasticity (0.86), followed by modulus of rupture (0.84) and density (0.79). The validation of the models showed that the average accuracies of predictions were 20.3 kg/m3 for density, 1.1 GPa for modulus of elasticity, and 6.1 MPa for modulus of rupture. Results are comparable to what has been found for other tree species, such as Pinus...

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

Journal of Spectroscopy, 2018

Near-infrared (NIR) spectroscopy provides a rapid alternative to traditional methods of wood property assessment. For organizations who assess wood properties on a large scale, multisite, multispecies calibrations are of practical interest. We examined NIR spectroscopy for the estimation of density (at 12% moisture content), modulus of elasticity (MOE), and modulus of rupture (MOR) using clear wood samples obtained from several pine species (Pinus caribaeavar. bahamensis, var.hondurensis, and var. caribaea, P.chiapensis,P.maximinoi,P.oocarpa,P.taeda, andP.tecunumanii). We compared different methodologies for collecting spectra, that is, benchtop instrument versus benchtop fiber-optic probe and field portable fiber-optic probe, and different wood surfaces (radial and transverse). Calibrations based on the benchtop instrument were superior to those obtained using the fiber-optic probe systems. Difficulty with adequately representing the sample when collecting spectra using a fiber-opt...

Traditions, anomalies, mistakes and recommendations in infrared spectrum measurement for wood

Wood Science and Technology

This paper deals with the difficulties of infrared spectroscopy measurement and suggests ways of dealing with them. Many problems appear when applying ATR (attenuated total reflection) measurement for determining the absorbance spectrum of wood, especially the highly porous nature of wood which does not fulfil the requirements of ATR measurement. Correct ATR spectrum determination requires wavelength dependence correction, but some authors miss out doing this. Normalisation of the infrared (IR) spectrum is a useful data manipulation method for correct evaluation of the spectra, but the incorrect normalisation can destroy the spectrum preventing the evaluation of the spectrum appropriately. Examples are given to teach the correct normalisation process. The difference spectrum method is an excellent tool to present the changes in IR spectra, but only a few scientists use it. Usage of wavenumbers during IR spectrum presentation is a traditional method nowadays. However, the usage of wa...