Nuclear Instruments and Methods in Physics Research A 463 (2001) 175–182 Remote particle density calibration of a water Cherenkov detector using crossing-through muons P. Bauleo*, C.B. Bonifazi, A. Filevich 1 , A. Reguera Departamento de F! ın Nacional de Energa Atmica, Avenida del Libertador 8250, 1429 Buenos Aires, Argentina For the Auger collaboration 2 Received 27 September 2000; accepted 9 November 2000 Abstract During the construction of the southern component of the Pierre Auger Observatory 1600 surface detector stations will be deployed, over an area of 3000 km 2 , near the town of Malarge, Mendoza, Argentina. In order to keep the whole system running efficiently during its expected lifetime of 20 years it is very important to be able to monitor the detector behavior remotely. Furthermore, remote calibration of the detector stations will be mandatory. In this paper we propose, from experimental grounds, a simple method for remote calibration of the detected particle density using the normally present background cosmic radiation. # 2001 Published by Elsevier Science B.V. PACS: 29.40.k; 06.20.F Keywords: Water Cherenkov detector; Auger project *Corresponding author. E-mail address: bauleo@tandar.cnea.gov.ar (P. Bauleo). 1 Fellow of the CONICET, Argentina. 2 Argentina: CRICyT Mendoza, Fisica & Ingenieria Universidad Nacional de La Plata, IAFE Buenos Aires, IAR Villa Elisa, Instituto Balseiro-CNEA & UNC Bariloche, Tandar-CNEA Buenos Aires, UTN Mendoza and San Rafael; Armenia: Yerevan Physics Institute; Australia: University of Adelaide; Bolivia: University of La Paz; Brazil: University of Campinas, University of Sao Paulo, CBPF-Lafex Rio de Janeiro, Federal University Rio de Janeiro; China: IHEP Beijing; France: ENST Paris, LTF Observatoire de Besancon, Collge de France, LPNHE Universit Paris 6; Germany: FZK-HPE and FZK-IK Karlshruhe, Universitat Karlsruhe; Greece: NTU Athens; Italy: INFN Catania, University of Milano, University of Roma 2, University of Torino; Japan: ICRR Tokyo; Mexico: BUAP Puebla, CINVESTAV-IPN, UNAM, UMSNH Morelia; Poland: INP Jagiellonian University Krakow, University of Lodz; Russia: MEPhI Moscow; Slovenia: Nova Gorica Polytechnic; UK: University of Leeds; USA: University of Colorado Boulder, EFI University of Chicago, FNAL, Louisiana State University, Michigan Technological University, University of New Mexico, Northeastern University, Pennsylvania State University, University of Utah; Vietnam: DNRI- VAEC Dalat, HINCST-VAEC, Hanoi. 0168-9002/01/$-see front matter # 2001 Published by Elsevier Science B.V. PII:S0168-9002(01)00288-1