Abstract
Results of a theoretical and experimental investigation of THz detection
of randomly-oriented metal particles smaller than 1 mm embedded in
pressboard are reported and critically compared with X-ray scanner
results. A theoretical description based on Gaussian beam theory and a
transfer function approach enabled simulation of signals transmitted
around and reflected from real particles and was able to predict signal
detectability. Simulated signals and detection limits were compared with
experimental transmission and reflection time domain spectroscopy (TDS)
raster scanning data. Simulated and measured pulse amplitude and shape
were in agreement. Reflection mode was superior to transmission mode in
terms of both particle visibility and hit ratio. Imaging of particles
was also possible in “reflection in transmission” mode, which can be
used to complement classical transmission mode. X-ray images did not
detect the smallest particles sufficiently and, therefore, could not be
used as reference data for comparison with THz data. The results
demonstrate that TDS reflection scanning is able to determine the
position of small metal particles and the technique could be possibly
used for quality control of pressboard insulation.
Read full article here
No comments:
Post a Comment