On-line measurements of resistance and temperature in melt-spun Cu90Co10 ribbons are made using two different annealing techniques: conventional furnace annealing, and linearly varying current Joule heating. The aim of this paper is to consider the electrical current, flowing through the sample during the annealing, as a possible parameter to control thermal treatment parameters and thus the microstructure of these systems. Although an exact way to obtain the temperature fromthe annealing current remains a difficult task, the on-line changes in resistance with current allows one to identify structural changes in the sample during annealing. Also, because the temperature is found to increase continuously with electrical current, it is possible to calibrate the Joule heating system to precisely determine the annealing temperature.