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Porous materials are widely used in acoustic and thermoacoustic applications due to their ability to dissipate acoustic energy through viscous and thermal interactions between the fluid and the solid skeleton. These mechanisms are commonly described by visco-thermal parameters such as the viscous resistance and the thermal relaxation conductance, which play a central role in equivalent fluid models of porous media. However, their direct experimental determination remains challenging.This work presents two experimental methodologies enabling the estimation in the low frequency regime of viscous resistance and thermal relaxation conductance in porous materials subjected to oscillating flow. The techniques rely on acoustic pressure measurements performed in a modified two-microphones technique in a standing wave tube. Two different measurement configurations allow the viscous and thermal contributions to be independently evaluated.The proposed approach is tested experimentally on a polyester fibers sample. The results show good agreement between experimental estimations and theoretical predictions, demonstrating that the proposed methods allow direct estimation of visco-thermal parameters of porous materials. The presented techniques provide a useful experimental tool for the characterization of porous materials in acoustic and thermoacoustic applications.