Despite a long tradition of dust instruments flown on-board space mission, the largest number of these can be considered unique as they used different detection techniques. GIADA (Grain Impact Analyzer and Dust Accumulator), is one of the dust instruments on-board the Rosetta spacecraft and is devoted to measure the dust dynamical parameters in the coma of comet 67P/Churyumov-Gerasimenko. It couples two different techniques to measure the mass and speed of individual dust particles. We report here the results of an extended calibration activity carried-out, during the hibernation phase of the Rosetta mission, on the GIADA Proto Flight Model (PFM) operative in a clean room in our laboratory. The main aims of an additional calibration campaign are:to verify the algorithms and procedures for data calibration developed before Rosetta launch;to improve the comprehension of GIADA response after the increased knowledge on cometary dust, e.g. the composition of dust particles after Stardust mission.These calibration improvements implied a final step, which consisted in defining transfer functions to correlate the new calibration curves obtained for the GIADA PFM to those to be used for GIADA onboard the Rosetta spacecraft. The extended calibration activity allowed us to analyze GIADA data acquired in the 67P/C-G coma permitting to infer additional information on cometary dust particles, e.g. density and tensile strength. © 2016 IAA. Published by Elsevier Ltd. All rights reserved.

GIADA was built by a consortium led by the Universit'a degli Studi di Napoli Parthenope and INAF – Osservatorio Astronomico di Capodimonte, in collaboration with the Instituto de Astrofisica de Andalucia, Selex-ES, FI, and SENER. GIADA is presently managed and operated by Istituto di Astrofisica e Planetologia Spaziali-INAF, Italy. GIADA was funded and managed by the Agenzia Spaziale Italiana, with the support of the Spanish Ministry of Education and Science Ministerio de Educacion y Ciencias (MEC). GIADA was developed from a Principal Investigator proposal from the University of Kent; science and technology contributions were provided by CISAS, Italy; Laboratoire d‘Astrophysique Spatiale, France, and institutions from the UK, Italy, France, Germany, and the USA. Science support was provided by NASA through the U.S. Rosetta Project managed by the Jet Propulsion Laboratory/ California Institute of Technology. We would like to thank A. Coradini for her contribution as a GIADA Co-Investigator. GIADA calibrated data will be available through ESA's Planetary Science Archive (PSA) Web site (www.rssd.esa.int/index.php?~project=PSA&page=index). All data presented here are available on request before archival in the PSA. This research was supported by the Italian Space Agency (ASI) within the ASI-INAF agreements I/032/05/0 and I/024/12/0.