A method of dynamically determining a modulus of elasticity of a moving web material
using web tensions and web velocities. The tension and velocity of a moving web
are determined in a first span. The tension and velocity of the moving web are
also determined for the moving web in a second span. A value analogous to the modulus
of elasticity of the moving web may then be determined according to the tension
and velocity values for the moving web in the two spans.