Muon radiography is an imaging technique that relies on the transmission of cosmic muons through matter. It allows the measurement of density maps of large structures such as volcanoes. During the second half of 2013 the MURAY detector prototype it carried out a data taking the Puy de Dôme in the framework of the scientific collaboration with the experiment TOMUVOL in order to compare the results and performance of the two different detectors. Both experimental apparatuses measure a transmission of some orders of magnitude higher than that expected highlighting a background that perturbs these measures.