  This paper presents a practical application of the concept of Optimal
Experiment Design (OED) for the determination of properties of porous materials
with in-situ measurements and an identification method. First, an experimental
set-up was presented and used for the measurement of relative humidity within a
wood fibre material submitted to single and multiple steps of relative humidity
variation. Then, the application of OED enabled to plan the experimental
conditions in terms of sensor positioning and boundary conditions out of 20
possible designs. The OED search was performed using the Fisher information
matrix and a priori knowledge of the parameters. It ensures to provide the best
accuracy of the identification method and thus the estimated parameter. Optimal
design results have been found for single steps from the relative humidity phi
= 10 to 75%, with one sensor located at the position X between 4 and 6 cm, for
the estimation of moisture permeability coefficients, while from phi = 75% to
phi = 33%, with one sensor located at X{\deg} = 3 cm, for the estimation of the
advection coefficient. The OED has also been applied for the identification of
couples of parameters. A sample submitted to multiple relative humidity steps
(phi = 10-75-33-75%) with a sensor placed at X{\deg} = 5 cm was found as the
best option for determining both properties with the same experiment. These OED
parameters have then been used for the determination of moisture permeability
and advection coefficients. The estimated moisture permeability coefficients
are twice higher than the a priori values obtained using standard methods. The
advection parameter corresponds to the mass average velocity of the order of v
= 0.01 mm/s within the material and may play an important role on the
simulation of moisture front.
