The paper analytically modeled experiment pseudoelastic alloy with shape memory (SPF), occurring at low temperature fluctuations. The dependence of the axial deformation of the voltage in the sample. Numerically investigated the stability of the process and the effect of the amplitude of temperature fluctuations on its parameters – area of the loop and voltage characteristic. It is shown that if the temperature and voltage changes sequentially, in the real phase transitions are triggered by temperature fluctuations, rather than loading and unloading, both in the ideal isothermal conditions. For this class of perturbations of the process instability is detected, but its characteristics are significantly dependent on the amplitude of the temperature fluctuations.