  SARG is the high resolution spectrograph of TNG. It has been in operation
since late spring 2000. SARG is a cross dispersed echelle spectrograph; it
offers both single object and long slit (up to 26 arcsec) observing modes
covering a spectral range from {\lambda}=0.37 up to 1 {\mu}m, with resolution
ranging from R=29,000 up to R=164,000. Cross dispersion is provided by means of
a selection of four grisms; interference filters may be used for the long slit
mode (up to 26 arcsec). A dioptric camera images the cross dispersed spectra
onto a mosaic of two 2048x4096 EEV CCDs (pixel size: 13.5 {\mu}m) allowing
complete spectral coverage at all resolving power for {\AA} <0.8 {\mu}m. An
iodine-absorbing cell allows to obtain high precision radial velocities. A
Distributed Active Temperature Control System (DATCS) maintains constant the
temperature of all spectrograph components at a preset value. Early results
show that SARG works according to original specifications in terms of
wavelength coverage, efficiency (measured peak efficiency is about 13%),
resolution (maximum resolution R~164,000 using a 0.3 arcsec slit, R~144,000
using an image slicer), and stability (preliminary estimates of the radial
velocity accuracy is ~5 m/s using the iodine cell and ~ 150 m/s without the
cell).
