The present paper describes a concept (reference 1) for accommodation of optical diagnostics around a fluid filled experiment cell in a facility for observation of fluid physical phenomena in a microgravity environment The concept includes video observation of an experiment cell interior, interferometry and IR thermography along two directions and tracer observation with light sheets along three directions, in a FOV of 10x10 cm2 maximum. The optics are arranged in various exchangeable modules to attain flexibility for instrument upgrading and ease of maintenance. Whereas midterm results have been previously presented (reference 1), the present paper concentrates on the accommodation of the optical diagnostics related modules. A reduced set of diagnostics can be used during manual access of the experiment cell.