A double-twin sorption calorimeter for studies of hydration of powders and soft materials. The channel diameter is 28 mm. The calorimeter is equipped with two sorption cells, each consist of a sorption chamber (on top) and a vaporization chamber (bottom). The cambers are connected by tubes with varying diameters to control the ioele flow. The double twin calorimeter is inserted into an isothermal TAM 2277 calorimeter from Thermometric equipped with a nanoamplifier.