This European standard specifies a method based on water absorption with vacuum for the determination of the bulk density of granular refractory materials (grain density) having a grain size larger than 2 mm. NOTE: This method is proposed as an alternative to the method based on mercury displacement with vacuum described in EN 993-17 which is to be used as the referee method because of its reproducibility. However, mercury is known to be a hazardous substance and the method in this EN is recommended for all routine purposes.