CT40 can be used in scientific research institutes, laboratories, blood stations, hospitals, disease control and prevention centers and reproductive centers for the storage of blood bags, biological samples, biological materials, vaccines, reagents, embryos, etc., it is an ideal way to maintain the activity of these sample. For reproductive center with big sample size, it can integrate GPS positioning system, voice prompts and screen flicker function together to locate the position of nitrogen storage dewar quickly and preciously.