[en] The emission spectrum from a plasma is often used to extract information on the hydrodynamic, radiative and atomic processes that take place. As these processes are coupled, detailed interpretation of spectroscopic data is often complex and uncertain. We present an experiment and modelling study of a 'simple' hydrogen and helium-like plasma. The target and laser geometry were designed to minimise spatial gradients transverse to the plasma flow. The plasma was spatially and temporally diagnosed using Thomson scattering, X-ray imaging and spectroscopic measurements. The combination of the optical and X-ray results constrains the numerical modelling to provide a more reliable plasma diagnostic. This is essential for the interpretation of high-resolution measurements and of more complex, non 1-dimensional plasmas. Optical parameters of the plasma parameters inferred independently of the X-ray measurements, were used to test the accuracy of hydrodynamic simulations made using the EHYBRID code. The densities from EHYBRID were compared to those from planar MED103 simulations and found to be in reasonable agreement. The EHYBRID electron temperatures were found to be similar to values inferred from Thomson scattering measurements. These results suggest that EHYBRID can reasonably simulate the 1-dimensional plasma