The Rheometry Facility was established to characterize the stress/strain relationships and other rheological properties of complex fluids. It maintains an Anton Paar MCR 301 rheometer with fully automated measurement capabilities in both stress- and shear-rate-controlled modes. Tools for parallel plate, cone, and Couette measurement geometries are available with temperature-stabilized sample stages and solvent trap. The system also can apply electric fields (up to 5 kV) and magnetic fields (up to 1 T) to characterize electro-and magneto-rheological fluids.