The new TNG-DIMM: calibrations and first data analysis

Since 2011 a new differential image motion monitor (DIMM) works at Roque de los Muchachos Observatory close to Telescopio Nazionale Galileo (TNG). The purpose of this instrument is to provide useful information about the optical turbulence for the astronomical observations at TNG. We present the instrument and the first statistical results including a relationship between the principal components analysis of local-ground atmospheric parameters and seeing.