HR: 1340h
AN: OS43B-0554    [Abstracts]
TI: Mechatronic Integration of In-situ Chemical Sensors for Seafloor Observatory
AU: Yang, C
EM: ycj@zju.edu.cn
AF: The State Key Lab of Fluid Power,Zhejiang University, 38 Zheda Rd., Hangzhou, JZ 310027 China
AU: * Chen, Y
EM: ychen@zju.edu.cn
AF: The State Key Lab of Fluid Power,Zhejiang University, 38 Zheda Rd., Hangzhou, JZ 310027 China
AU: Gu, L
AF: The State Key Lab of Fluid Power,Zhejiang University, 38 Zheda Rd., Hangzhou, JZ 310027 China
AU: Ye, Y
AF: Department of Earth Sciences, Zhejiang University, 38 Zheda Rd., Hangzhou, JZ 310027 China
AU: Cao, J
AF: The State Key Lab of Fluid Power,Zhejiang University, 38 Zheda Rd., Hangzhou, JZ 310027 China
AU: Ding, K
AF: Department of Geology and Geophysics, University of Minnesota, 310 Pillsbury Dr. SE, Mpls, MN 55455 United States
AB: There is a great demand for in-situ real-time chemical sensors in seafloor hydrothermal vent studies. Some strict requirements must be satisfied for any sensor-data logging system deployed in this extreme conditions: more than one chemical species along with temperature should be simultaneously measured and recorded; the acquired signals need to be amplified, regulated, and stored in the memory inside the pressure chamber of small size and low power consumption. During a recent Alvin/Atlantis cruise, newly developed chemical sensor and self-contained multi-channel data logging instruments were tested at the depth of 2500 m to quantify variations in vent fluid chemistry. The units were placed at different vent sites taking data at a rate of 5 second per-scan and recording up to 13 days. The multi-channel sensor-data logger mainly consists of two parts: one part is the sensor housing (40 cm x 5 cm diameter), which includes a hemisphere-shaped case with a hole-pattern that allows simultaneous sealing of multiple-sensor and electrodes, a Ti jacket is installed for sensor protection; the other is the circuit housing (38 cm x 8 cm diameter), which can be easily connected to the sensors through a underwater connector and cable. For viewing real time data inside the submersible hull, the unit makes use of ICL communication. In the circuit housing, MSP430 is used as CPU on the electronic board with very low energy consumption. All electronic components use chip encapsulation to make the electronic board much more compact, meanwhile a 4M interior storage is designed for the board. Currently 4 chemical sensors and 2 temperature sensors can be connected to the data logger for simultaneous data scanning with signal ranging from ?.25V to 1.25V at a tolerance of less than 1mV. 3 1.5V DC batteries are used for the circuit board and 3 high energy 3.6V batteries are used for the ICL system. Thus, sensor signals sampled in half an hour intervals permit the unit to operate for over a year. The total weight of the sensor-logger unit is less than 8 kg, so it can be easily taken by various submersibles to seafloor vent system.
DE: 4825 Geochemistry
DE: 4832 Hydrothermal systems
DE: 4894 Instruments and techniques
DE: 4594 Instruments and techniques
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting