Fig. 6

View of the sensors in the repair of a sandstone in a buttress. The stone is exposed to the environment on two sides. The repair is equipped with frames for gathering the run-off water, which is used to quantify the absorbed water and the wind-driven rain, and sensors of temperature and relative humidity at the surface and at depths of 1.0, 2.5, 4.0 and 6.7 cm. The same sensors are used in a neighbouring stone that had not been repaired