Surface gravity is plotted against effective temperature. The diamonds mark the programme stars from our sample. Zero age extreme horizontal branch (ZAEHB) and terminal age extreme horizontal branch (TAEHB) are plotted as well as the helium main sequence (HeMS). Tracks for canonical EHB stars are taken from Dorman et al. (1993). The sample covers the whole parameter range on the EHB and also subdwarfs that already evolved away from the EHB.