NMR (Nuclear Magnetic Resonance) is a form of radio-frequency spectros
copy in strong magnetic fields. Different NMR parameters correspond to
crosslink density, and carbon-black filled elastomers are transparent
to radio frequency, so that NMR can be employed for determination of
crosslink densities. Three-dimensional spatial resolution can be gener
ated based on the principles of magnetic resonance imaging known in me
dical diagnostics, or a novel sonde can be positioned on the object, b
y which crosslink densities can be determined locally with limited dep
th resolution.