  It is shown that different pairs of stress-energy and spin tensors of quantum
relativistic fields related by a pseudo-gauge transformation, i.e. differing by
a divergence, imply different mean values of physical quantities in
thermodynamical nonequilibrium situations. Most notably, transport coefficients
and the total entropy production rate are affected by the choice of the spin
tensor of the relativistic quantum field theory under consideration. Therefore,
at least in principle, it should be possible to disprove a fundamental
stress-energy tensor and/or to show that a fundamental spin tensor exists by
means of a dissipative thermodynamical experiment.
