9 electrical, electronic, measuring, signalling devices and instruments, namely, electrodes, cables, grids formed by electrodes or cables, nets formed by electrodes or cables, cable connections, underground cable grids, electrical and electronic detectors, measuring amplifiers, measuring transformers, transducers, bus lines, modems, signal horns, signal lamps, electrical and electronic switch boxes, data plotters, data recorders, computers, all aforesaid goods for use in environmental protection, waste disposal, detection and location of leaks and/or for checking the integrity of lining systems