A measurement apparatus for determining the position of an object relative to a reference surface, with a measurement nozzle, a reference nozzle, and a measurement device, the outlet opening of the measurement nozzle being located in the reference surface. A barrier layer is formed over a bond pad. The database controller includes a storage request receiver configured to receive a request to store a triple in the database, and a data item generation module configured to generate two or more data items each having a different version of the triple. The test apparatus generates at a regular frequency synthetic status data relating to the alarm point and transmits the synthetic status data to the data-collection apparatus. The battery rack management systems are also connected to a main battery management system configured to minimize voltage deviations between the battery racks.