The surface detector of the Pierre Auger Observatory will consist of 1600 water Cherenkov tanks sampling ground particles of air showers produced by energetic cosmic rays. The construction of the array is nearly completed and a large number of detectors have been operational for more than three years. In this paper the performance of different components of the detectors are discussed. The accuracy of the signal measurement and the trigger stability are presented. The performance of the solar power system and other hardware as well as the water purity and its long-term stability are discussed.

The Pierre Auger Collaboration

Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 4 (HE part 1), pages 311-314