Described is a detachable fixture for a rotational rheometer, the Sentmanat Extensional Rheometer Universal Testing Platform, which incorporates dual wind-up drums to ensure a truly uniform extensional deformation during uniaxial extension experiments on polymers melts and elastomers. Although originally developed as an extensional rheometer, this highly versatile miniature test platform is capable of converting a conventional rotational rheometer host system into a single universal testing station able to characterize a host of physical properties on a variety of polymer melts and solid-state materials over a very wide range of temperatures and kinematic deformations and rates. Experimental results demonstrating these various testing capabilities are presented for a series of polymers of varying macrostructure and physical states.