1. Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Qingdao 266000, China
2. R & D Center for Marine Instruments and Apparatuses, Laoshan Laboratory, Qingdao 266235, China
3. Key Laboratory of Polar Science, Ministry of Natural Resources, Polar Research Institute of China, Shanghai 200136, China
4. College of Environment and Safety Engineering, Qingdao University of Science and Technology, Qingdao 266042, China