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
Rio–Antirrio bridge and a pedestrian walkway. Its five-span four-pylon cable-stayed portion of length is the world's third longest cable-stayed deck; only the decks of the Jiaxing-Shaoxing Sea Bridge in Shaoxing, China and the Millau Viaduct in southern France are longer at 2,680 m (8,793 ft) and , respectively. However, as the latter is also supported by bearings at the pylons apart from cable stays, the Rio–Antirrio Bridge deck might be considered the longest cable-stayed "suspended" deck. This bridge is widely considered to be an engineering masterpiece, owing to several solutions applied to span the difficult site. These difficulties include deep water, insecure