The system testing/monitoring mould sand and humidification in the flask during the shakeout stage is controlled automatically by an extremely modern GSC system. A tester is installed at the muller delivery point and picks up and tests, for each mulling, establishing the parameters that characterise the quality of the moulding sand. The data are acquired and processed by means of a powerful PLC capable of making the necessary variations to the additives to be added to the muller in order to maintain the characteristics of the moulding sand, keeping them within a restricted range fixed by the foundry technical office. Following shakeout, the sand is very dry and drastically deprived of its fundamental characteristics when coming into contact with the liquid cast iron in the casting. At the shakeout drum input point, with the use of a set of temperature and humidity gauges, the system manages to determine the characteristics of the shaken out sand and calculate, with the aid of PID algorithms, the quantity of water to be added to cool the sand and to reactivate part of the bentonite contained in it. The system also controls the humidity of the air released by the filter, which is reduced to ensure that as much of the water added to improve the cooling of the sand as possible is evaporated. This is achieved by hot air blowing inside the drum and a powerful extraction fan fitted with a bag filter. The filter extracts the powders contained in the sand, increasing permeability which is a fundamental feature of the quality of the sand. The conditions of the sand fed from the drum are detected by a second battery of sensors. The data readings are processed by the system, which then corrects the humidity level of the sand by adding a quantity of water to the sand as it is fed out of the drum