The received signal strength based radio tomographic imaging recently gained momentum as an unobtrusive localization method. The localization accuracy performance evaluation of such systems require complex experiment campaigns. In particular, performance dependence on the test subject parameters should be considered. In this work, we introduce a radio tomographic imaging experimentation system based on an autonomously navigating robot. The robot is equipped with a cylindrical container filled with a special liquid simulating human tissue at 2.4 GHz. We use this system to assess localization accuracy of different imaging methods. The results suggest that Network Shadowing model based method performs as good as more complex methods.