1. With the United States imported high precision pressure sensor and no oil vacuum pump. Low noise, high precision.2.Imported electromagnetic valve and stainless steel vacuum container to ensure that equipment sealing performance, make the results more accurate and stable.3.Liquid crystal display in Chinese, friendly man-machine interface, automatic test, has the function of test data statistical processing, micro printer output.4.Set up according to the smoothness of the high and low three gears test more rapid and accurate.