A sample chamber assembly for molten metal comprises a cover plate and a housing. A first face of the housing has a depression in direct flow communication with a first opening formed at the immersion end of the housing. The cover plate and the housing are assembled together along a first plane to form a sample cavity including the depression. An analysis surface of a solidified metal sample lies in the first plane. The sample cavity and the first opening are aligned along a common longitudinal axis. The first opening is spaced apart from the first plane. A ratio of the thermal diffusivities of the solidified metal sample and the housing material is between 0.1 and 0.5. The housing is inseparable from the solidified metal sample. A portion of the housing is directly adjacent to the solidified metal sample and lies in the first plane.