In-situ monitoring of temperature and micro-strain during chemical corrosion of stone cultural relics by fiber Bragg gratings

To obtain in situ real-time information on temperature and micro-strain changes in the body of stone cultural relics during chemical corrosion damage, a fiber Bragg grating (FBG) detection system was prepared. A theoretical model of the sensor to monitor the temperature and micro-strain was established. The temperature and micro-strain changes of the sandstone samples under deionized water with alkaline solutions and temperatures were examined online in-situ using the FBG measurement system. The results show that the material conversion exothermic chemical reaction between sandstone and NaOH solution and the reaction with deionization are dissolution reactions.