A foam rheometer has been developed based on the impulse theory of lin
ear viscoelasticity. The rheometer is a large-volume parallel-plate de
vice which operates under gap-loaded conditions, and is designed as an
add-on fixture for the Materials Testing System Model 312. The rheome
ter provides characterization data of the pre-gel (via the zero-shear
viscosity) or the post-gel (via the equilibrium modulus) properties of
a foaming cellular polymer with a precision of better than +/- 15%