Fundamental stellar parameters of benchmark stars from CHARA interferometry

Large spectroscopic surveys of the Milky Way need to be calibrated against a sample benchmark stars ensure reliable determination atmospheric parameters. We present new fundamental stellar parameters seven giant and subgiant that will serve as benchmarks. The aim is reach precision 1% in effective temperature. This essential for accurate determinations full set abundances observed by surveys. HD121370 (etaBoo), HD161797 (muHer), HD175955, HD182736, HD185351, HD188512 (betaAql), HD189349 using high angular resolution optical interferometric instrument PAVO/CHARA. limb-darkening corrections were determined from 3D model atmospheres based on STAGGER grid. Teff directly Stefan-Boltzmann relation, with an iterative procedure interpolate over tables bolometric corrections. estimated surface gravities comparisons Dartmouth evolution tracks. observations collected ELODIE FIES spectrographs. metallicities ([Fe/H]) 1D non-local thermodynamic equilibrium (NLTE) abundance analysis unblended lines neutral singly ionised iron. For six we measure better than 1%. one star, HD189349, uncertainty 2% due uncertain flux. do not recommend this star until measurement can improved. Median uncertainties all logg [Fe/H]} are 0.034dex 0.07dex, respectively. All consistently combining observations, modelling analysis. paper follows our previous papers including dwarfs metal-poor stars.