The Laboratory Mortar Mixer is equipped with a torque sensor, a control unit and a water dosing system. A specific amount of standardized sand and cement are put into the bowl. After some time of dry mixing, a precise amount of water is added, which increases the force for mixing significantly. The mixing force is constantly measured by the torque sensor. More water is added to the mortar and the torque starts to decrease. The so called Water Demand, which is the main result of this measurement, is the total amount of water, which has to be added until the torque comes down to the specified torque value.