Paper 5: Volume 4 No.4 March 2006 Edition
Computed Tomography for Indoor Applications
M. Cehlin1
and M. Sandberg2
1Divison
of Energy and Mechanics, Department of Technology and Built Environment,
University of Gävle
,
Sweden
.
2Division
of Indoor Environment,
Institute
of
Technology
and Built Environment,
University
of
Gävle
,
KTH Research School
,
Sweden
Abstract
This paper deals with tomographic techniques for two-dimensional
spatially resolved concentration measurements indoors. This represents a
significant advance over the traditional point measuring method for
mapping tracer gas and pollutants. Methods for recording of data are
stressed as well as different types of tomographic reconstruction
algorithms such as the Smooth Basis Function Minimization (SBFM) and the
modified Low Third Derivative (LTDm) methods. Among the
reconstruction algorithms available today, SBFM and LTDm are
among the most promising. These algorithms show potential for
reconstruction of gas concentration in rooms, since they are regularized
to converge towards smooth concentration distributions. Using the LTD
method and ‘snapshot’ configuration enables the examination and
real-time monitoring of transient flows.
Key
words: computed
tomography, tomographic reconstruction algorithms, pollution distribution
monitoring, laser scanning.
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