  We examined the affection of the flux-trapped states of Sn60-Pb40 solders on
superconducting properties of a Sn wire. The temperature dependence of
electrical resistivity at H = 0 Oe after zero-field cooling (ZFC) showed a
sharp superconducting transition at T = 3.7 K. In contrast, that after field
cooling (FC) resulted in broadening of the transition. The difference between
ZFC and FC data evidences critical affection of trapped fluxes at solders on
superconducting states. We propose that, in electrical measurements where
magnetic fields of several hundred Oe are critical, field experience should be
seriously considered when using solders.
