Simplest way for verification of BCS theory of superconductivity

From the BCS theory of superconductivity is well known that the superfluid density smoothly decreases with increasing temperature. This means that some superfluid carriers annihilate when heated, become normal and, thus, dissipate their (angular) momenta on atom lattice.

We can induce a persistent supercurrent (much weaker than a critical current) in a massive ring below Tc. After that we slowly increase the temperature, and then we must observe a smooth decrease in the actual supercurrent, because the momenta of the annihilated electron pairs vanish on the lattice, reducing the total supercurrent momentum.

Thus, we can show that the microscopic BCS approach is in line with the macroscopic effect in superconductors, reducing strongly doubts and debates on the issue.