Generally speaking, monitoring the stability of a structure from a static point of view involves the control in the course of time of those warning signs such as cracks or damage with the purpose of establish their actual origins, e.g. soil instability, degradation of building materials and so on. This is firstly achieved through the installation of a number of specific sensors dedicated to the control of different parameters whose readings are then sent to and stored by a multi-channel acquisition unit. Data loggers may be locally or remotely run and recorded readings may even be automatically sent to a server accessible from any internet point to accredited operators.
The electric sensors most frequently used are displacement transducers, uniaxial and biaxial clinometers for controlling the progress of cracks and rotational movements in civil or hystorical structures. Sometimes also hydraulic settlement sensors or multi-base extensometers are installed, particularly for monitoring vertical movements of a structure. Data loggers may be implemented with alarm devices, activated when critical threshold values which can bring to a failure of the monitored structure, are reached.