Microwave sensors for scanning of sawn timber

• A microwave imaging sensor that measures the signal transmitted through a board was investigated with respect to the ability to predict the distribution of moisture and density in sawn lumber. Furthermore, the response from the sensor was related to strength properties of the boards. Multivariate statistics was used to relate the measured variables to various properties. A finite element model based on X-ray computed tomography images was developed to describe the interactions between microwaves and wood. The model made it possible to simulate the response from the sensor under varying conditions. The results show that microwaves can be used for prediction of density and moisture content. They can also be used for prediction of strength properties, mainly from the correlation to density, but also from the influence on microwaves of structural variations in the wood. The finite element model is useful in the evaluation of microwave sensors for wood, drying equipment or other applications where electromagnetic waves interact with wood.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Elektroteknik och elektronik -- Reglerteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Electrical Engineering, Electronic Engineering, Information Engineering -- Control Engineering (hsv//eng)

TEKNIK OCH TEKNOLOGIER  -- Maskinteknik -- Annan maskinteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Mechanical Engineering -- Other Mechanical Engineering (hsv//eng)

Nyckelord

microwave scanning; wood; density; moisture content; strength grading; finite element

Electronic measurement and instrumentation

Elektronisk mät- och apparatteknik

Träteknik

Publikations- och innehållstyp

vet (ämneskategori)

dok (ämneskategori)