Knowledge of the value of axial tensile force acting on the metal chains of an historic building is of paramount importance for the evaluation of the stress present in it. The presence of non-tensioned chains could lead to errors in the evaluation of real structural behavior and of the stresses transmitted by pushing structures such as arches and vaults.
The axial force acting in an existing chain cannot be assessed by means of direct methods of measurement; it is therefore necessary to resort to indirect methods which are based on the measurement of physical quantities strictly correlated to the force traction. This can be done by mean of the dynamic method.
Among the advantages of the dynamic method there is the simplicity of application and processing of the data collected at the construction site.