Measuring environmental impact by real time laser differential displacement technique in simulated climate conditions

Environmental impact on artworks has always been a big issues for preservation of Cultural Heritage. Nowadays with the climate change it is experienced a slow but steady process of temperature increase affecting relative humidity which fluctuates while materials attempt to keep moisture balance. During repetitive equilibrium courses fatigue accumulates endangering the structural integrity prior to fracture. Assessing the risk imposed by the fluctuation allow preventive actions to take place and avoid interventive restoration action after fracture. A methodology is presented employing full-field interferometry by surface probing illumination based on direct real-time recording of surface images from delicate hygroscopic surfaces as they deform to dimensionally respond to relative humidity (RH) changes. The developed methodology aims to develop an early stage risk indicator tool to allow preventive measures directly through surface readings. The presented study(1) aiming to experimentally highlight acclimatisation structural phenomena and to verify assumed standards in RH safety range based on the newly introduced concept of deformation threshold value is described and demonstrated with indicative results.