Experiments were performed in the Pilot-PSI linear plasma device, to determine the sheath heat transmission coefficients in a high recycling regime under various conditions of density (1–20×1020m−3) and plasma composition (H2,Ar,N2) relevant for the ITER divertor plasma. The 2D surface temperature profile on a tungsten surface was measured with high spatial (0.33mm) and temporal (200Hz) resolution using an infrared camera. The target heat flux is calculated using a 2D axis-symmetric Ansys model, the heat transfer is determined from target calorimetry. The plasma parameters are measured with a high resolution Thomson scattering system located 17mm away from the target surface. Radial profiles of the sheath heat transmission factors can thus be determined.Preliminary results show that γ varies between 4 and 40 depending on the plasma conditions and composition. The value derived from the heat flux calculated with Ansys is significantly lower than theory predicts.