This European Standard describes a method of measuring the heat of hydration of cements by means of semi-adiabatic calorimetry, also known as the Langavant method. The aim of the test is the continuous measurement of the heat of hydration of cement during the first few days. The heat of hydration is expressed in joules per gram of cement. This standard is applicable to all cements and hydraulic binders, whatever their chemical composition, with the exception of quick-setting cements. NOTE 1 An alternative procedure, called the solution method, is described in EN 196-8. Either procedure can be used independently. NOTE 2 It has been demonstrated that the best correlation between the two methods is obtained at 41 h for the semi-adiabatic method (EN 196-9) compared with seven days for the heat of solution method (EN 196-8).