UWB Radio Measurement and Time-Domain Analysis of Anisotropy in Wood Chips

• Ultra-wideband (UWB) radio transmission measurements have been used to determine the moisture content of wood chips using a time domain technique. Wood chips have been found to have birefringent dielectric properties acting as an anisotropic dielectric effective medium. Birefringence in wood chips occurs because of the orientation and the shape of wood chips, and microscopic structures of these objects, like wood fibers. The birefringence gives rise to two different wavefronts along the principal axes that have different dielectric properties. Each wavefront has a specific time-domain signal, that can be used to determine the moisture content. In industrial applications, for example in measurement on wood chips in trucks, the vertical polarization direction is the preferable polarization because this signal has higher signal-to-noise ratio (SNR), which makes the signal more identifiable at longer distance (2-3 m). Thus, UWB radio transmission measurement and time-domain analysis is a robust technology to investigate larger containers of wood chips and to determine the moisture content with high accuracy.

Ämnesord

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

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

Nyckelord

anisotropy

birefringence

moisture content

non-destructive testing

radio measurement

Time-domain

transmission measurement

UWB

wood chips

Anisotropic media

Dielectric properties

Moisture

Moisture determination

Nondestructive examination

Polarization

Radio transmission

Signal to noise ratio

Ultra-wideband (UWB)

Underwater acoustics

Wavefronts

Wooden containers

Non destructive testing

Radio measurements

Time domain

Transmission measurements

Wood chip

Time domain analysis

Intelligent industri

Intelligent Industry

Publikations- och innehållstyp

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