Millau Viaduct slightest movement in the Viaduct, and measure its resistance to wear-and-tear over time. Anemometers, accelerometers, inclinometers, temperature sensors are all used for the instrumentation network. Twelve fibre optic extensometers were installed in the base of pylon P2. Being the tallest of all, it is therefore under the most intense stress. These sensors detect movements on the order of a micrometre. Other extensometers, electrical this time, are distributed on top of P2 and P7. This apparatus is capable of taking up to 100 readings per second. In high winds, they continuously monitor the reactions of the Viaduct to extreme conditions. Accelerometers
Pfrimm Viaduct Pfrimm Viaduct The Pfrimm Viaduct (), colloquially also called the Marnheim Bridge ("Marnheimer Brücke"), was a railway bridge near Marnheim in the county of Donnersbergkreis in the German state of Rhineland-Palatinate. It was built as a stone arch and truss bridge from 1872 to 1874, was 260 metres long and 30 metres high, and carried the Donnersberg Railway from Hungerberg over the valley of the Pfrimm to the Zeller Valley Railway, which is only open at weekends today. The bridge is a protected monument and forms the "Gateway to the Zellertal" ("Tor zum Zellertal"). The viaduct was built east of