Detailed knowledge of polymer crystallization kinetics is a mandatory requirement in modeling of transformation processes. On the other hand, techniques for investigation of crystallization kinetics are limited to cooling rates much lower than those experienced by the materials in industrial processes. A method suitable to investigate crystallinity evolution during cooling procedures carried out adopting rates comparable with those experienced by the polymer during industrial processes is thus extremely attractive. In this work a method is proposed, based on fast cooling of thin samples by means of air/water sprays and optical detection of the crystallization phenomenon. Preliminary results of crystallization temperatures detected with a device based on such a method are presented and, in the low cooling rate range, are compared favorably with calorimetric results. The comparison of experimental crystallization temperature with results of a kinetics model previously developed leads to satisfactory agreement.