1.1 ,These test methods describe how capillary rheometry may be used to measure the rheological characteristics of rubber (raw or compounded). Two methods are addressed: Method A—,using a piston type capillary rheometer, and Method B—,using a screw extrusion type capillary rheometer. The two methods have important differences, as outlined in 7 –, 10 and 11 –, 14, respectively.