Fig. 3From: Clustering analysis of acoustic emission signals in the monitoring of stone monuments: case of the freeze‒thaw deterioration of tuffsThe temperature data monitored from July 2020 to July 2021 for the outdoor pillar stone at the northwest corner of the Puyou Temple in Chengde. a Ambient temperature, b surface temperature, and c ambient temperature with the greatest diurnal on February 4th, 2021Back to article page