Shanghai ChangAi Electronic Science & Technology Co., Ltd. is a high-tech corporation that is specialized in studying, developing, producing and selling high quality sensors, analyzers & system engineering. Our main products include: Series dew point analyzer, series trace oxygen analyzer, high purity oxygen analyzer, portable oxygen analyzer, series nitrogen purity analyzer and trace hydrogen analyzer. And our products have been widely used in the fields of air separation, petrochemical industry, health, oil refining, and electronic power industry all over the world.