| Author | Jiang, Aidong |
| Call Number | AIT Thesis no.AE-94-44 |
| Subject(s) | Aquaculture
|
| Note | A thesis submitted in partial fulfillment of the requirements for the Degree of Master of Engineering. |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. AE-94-44 |
| Abstract | A microcomputer-based pond water quality sampling and control system has been in operation at AIT for research work for several years. The system samples water at multiple depths at programmable intervals. System controlled 12 V DC pumps deliver water to central flow cells which contain sensors for water quality analysis. The major objective of this work was to develop a compact, reliable water sampling subsystem of the total system. This thesis work reviewed previous similar systems; developed design criteria for an improved water sampling subsystem; described and considered several strategies to improve the subsystem; selected, produced and tested one new subsystem, and analyzed the results. Field observations show that aquaculture ponds often exhibit density stratification. In order to characterize a stratified water column, ponds of 1 meter depth may have to be sampled at five depths. Five small bilge pumps, each with a capacity of 25.4 I/min and 1 meter head, were selected. Five pumps with five check valves were installed to a support pipe at 5, 15, 25, 50, 75 cm depths. The water from five depths was pumped through the support pipe separately to the flow cell for analysis. The measured flow rate of the system is 14. 7 I/min. The developed system was tested continuously in two ponds each for 20 days without failure . To check the system's performance, temperature, dissolved oxygen and pH were measured manually. The data obtained from manual measurements agree well with those measured by the data acquisition system, indicating that the water sampling system was able to draw samples at five specified depths and record reasonable diel cycles at five depths. The weight of the developed water sampling system is 5 Kg and the overall dimensions are 110 cm x 40 cm X 8 cm. The total cost is about Baht 6,400, with Baht 3,400 for materials and Baht 3,000 for fabrication. The new system is simple, cheap, durable and easier to transfer. Further development of the system should include consideration of the orifice of the solenoid valves and the two pipes system. |
| Year | 1994 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. AE-94-44 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Food, Agriculture and Natural Resources (Former title: Department of Food Agriculture, and BioResources (DFAB)) |
| Academic Program/FoS | Agricultural and Food Engineering (AE) |
| Chairperson(s) | Singh, Gajendra |
| Examination Committee(s) | Szyper, James;Winden, J. Van;Salokhe, Vilas M. |
| Scholarship Donor(s) | DANIDA |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1994 |