Laboratory and In Situ Tests on an Automatic Monitoring System with IPIs

In order to gain some insight into the origin of noise of the automatic In-Place Inclinometer (IPI) measures at the Castelrotto landslide (Italy) a number of tests were carried out in the laboratory and in the field. The field tests involved: 1) measurement of the excitation voltage at the IPI position; 2) analysis of a steady electronic signal. Laboratory tests analyzed: 1) the type of excitation effects on the signal when changing the power system; 2) the effects of modes of acquisition when changing the frequency of acquisition and the warm-up time; 3) the effects of temperature when heating each component of the acquisition system. It was found that a) the most noise comes from the electrical connections, and b) temperature significantly affects the signal, by reacting mainly on the electrical links.