A burner and surrounding co-flow air system were developed for experimental study of flame suppression in a diluted oxygen environment. Development of the burner was guided by design criteria requiring the flame to be a turbulent buoyant diffusion flame in a line configuration presenting a realistic challenge to suppression methods such as oxidizer-stream dilution. Design constraints included buoyancy, turbulence, and flame height criteria. Oxygen concentration and temperature measurements, along with a smoke wire flow visualization technique were utilized to evaluate the system and ensure the design criteria were successfully met. Additional analysis was performed on image recordings of the flame to provide a robust and repeatable flame height measurement to evaluate the flame height constraint. Ultimately, an experimental apparatus with the ability to suppress a flame in a controlled, well-characterized environment was developed to provide a good base for model validation measurements.