9 Scientific, optical, measuring, signalling and checking (inspection) apparatus and equipment; data processing equipment and computers; computer software; alarms; sensors and detectors; level sensors; liquid level sensors; oil level sensors; fuel level sensors; mechanical, electric and electronic apparatus and instruments for measuring, detecting and monitoring liquid surface levels; apparatus and instruments for transferring, transforming into an editable format, logging and editing measurement data; telecommunications apparatus for the transmission of measurement and switch data; electric and data transmission cables and wires; wireless local area network devices; batteries; solar panels as power source; leak detectors; leak detection apparatus; fuel leak detection apparatus; chemical leak detection apparatus