Development of Non-invasive Measurement Systems for Water Content on the Surface of Mural Paintings

了解壁画表面的含水量和蒸发情况，对防止颜料脱落、盐分沉积、真菌滋生等具有重要意义。然而，由于在高湿度环境下的非侵入式测量是困难的，因此没有太多的研究。根据温度和相对湿度的测量值计算绝对湿度的梯度，确定石头表面的蒸发。这种方法的缺点之一是数据记录器的耐湿性差。选择了具有较好抗湿性能的温湿度传感器，开发了一种适用于潮湿场所的新系统。它由控制板Arduino Mega 2560组成，控制来自传感器的数字信号并将数据记录在微型SD卡上。在这项研究中的原型系统进行了评估。

It is important to understand the water content and evaporation on the surface of mural paintings in order to prevent from exfoliation of pigments, deposition of salts, fungi growth and so forth. However, there have not been many researches because non-invasive measurements in high-humidity environment are difficult.In this study, a measurement system was first constructed using two small data-loggers. Evaporation on the surface of the stone was identified from the gradient of absolute humidity calculated from measured values of temperature and relative humidity. One of the drawbacks of this method is that the data-logger is poor in humidity resistance. Temperature and humidity sensors, which have better humidity resistance, were selected to develop a new system for application at humid sites. It is composed of a control board Arduino Mega 2560, which controls the digital signals from sensors and records the data on a micro SD card. A prototype system was evaluated in this study.