A system for managing of bulk liquids and/or bulk solids for in-vitro diagnostics is disclosed. The system comprises a sample processing unit and a container unit for receiving a supply container supplying the sample processing unit with a bulk liquid/solid and/or a waste container receiving waste from the sample processing unit. The system further comprises a weight measuring device comprising a loading plate, a base and a force measuring cell. The force measuring cell comprises a sensor comprising a tensioned sensor wire. The loading plate is biased with respect to the base by a weight applied to the loading plate by a container and to transfer force to the force measuring cell. The transferred force causes a deformation of the force measuring cell and a change in tension of the sensor wire causing a change in vibrational frequency resulting in a signal indicative of the weight of the container.