Determination of moisture content and basic specific gravity ofPopulus tremuloides(Michx.) andPopulus balsamifera(L.) logs using a portable near-infrared spectrometer

Abstract

Portable sensors are required for rapid and nondestructive measurements of wood properties in the field to ensure optimal use of the fiber. We tested a handheld near-infrared (NIR) spectrometer to estimate moisture content (MC) and basic specific gravity (BSG) of quaking aspen (Populus tremuloides Michx.) and balsam poplar (Populus balsamifera L.) frozen and thawed logs. Partial least square (PLS) regression general models were developed to estimate MC and BSG by considering the influence of the following factors: log conditions (frozen and thawed wood), species, and types of wood (sapwood and heartwood). In addition, the influence of MC was also considered when estimating BSG. Including the two types of wood in a general model improved MC prediction (R 2 p ¼ 0.83, RMSE p = 11.1%) while including the two species improved BSG prediction (R 2 p ¼ 0.57, RMSE p = 0.022). Similar accuracies were obtained for BSG prediction from green (R 2 p ¼ 0.35, RMSE p = 0.027) and oven-dried wood (R 2 p ¼ 0.43, RMSE p = 0.027). PLS discriminant analysis was applied successfully to NIR spectra to sort the wood according to their MC, BSG, species, and wood type with overall accuracies of 86%, 65%, 98%, and 79%, respectively.

Development of calibration models for rapid determination of moisture content in rubber sheets using portable near-infrared spectrometers

“…The CH functional groups vibrated in the second and third overtone regions, around 1200 and 925 nm, 5 respectively, while around 1140 nm and 1351 nm, the CH 3 functional groups vibrated in the second overtone region, and at around 1659 nm in the¯rst overtone region. 29 In region 1400-1600 nm in Fig. 4, the lowest line (0.53%db) has the lowest absorbance value corresponding to the lowest moisture content, whereas the higher lines have higher absorbance associated with the higher moisture content of the samples.…”

“…4, the lowest line (0.53%db) has the lowest absorbance value corresponding to the lowest moisture content, whereas the higher lines have higher absorbance associated with the higher moisture content of the samples. The spectra were clearly di®erent in this region due to the water (OH functional groups) in the second overtone region, especially around 1410 nm 29 (Fig. 5) where a peak was visible.…”

Sensors in the Forest Products Industry

“…Several papers in the current issue use nearinfrared spectroscopy (NIRS) to predict wood properties, including moisture content and basic specific gravity in logs (Hans et al 2015a) and surface quality of aspen veneers (Koumbi-Mounanga et al 2015). NIRS-based hyperspectral images are used to estimate moisture content and density distributions in subalpine fir board (Haddadi et al 2015a, b).…”

Development of Low-Cost Portable Spectrometers for Detection of Wood Defects

“…However, its practical application in field/forest is challenging [9][10][11]. Portable NIR instruments were successfully used in the field for tree breeding [12][13][14], prediction of tracheid length [15], assessment of wood and fiber properties in standing mountain pine beetle-attacked trees [16], wood species recognition [17], wood moisture content prediction [18] and estimation of leaf quality [19]. However, until now, only a few applications have been implemented in real-world wood processing industries, mostly for on-line sorting of wooden products and quality control of production [20][21][22].…”