An Inexpensive, Low-Maintenance, Precision Amplifier, Dissolved Oxygen Sensor, and Miniature Data Logger System Designed for Long-Term Deployment in Riverine Systems
(一種廉價的,低維護,精密放大器,溶解氧傳感器,微型和數(shù)據(jù)記錄系統(tǒng),設(shè)計用于長期部署在河流系統(tǒng)。)
文獻:
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DOI:
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10.1577/T08-011.1
Lawrence W. Keenana & Steven J. Millera
Publishing models and article dates explained
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Received: 16 Jan 2008
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Accepted: 22 Oct 2009
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Published online: 09 Jan 2011
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The dissolved oxygen (DO) concentration is a dynamic water quality variable that is critical to fisheries. To obtain simultaneous DO data at 15-min intervals over long periods (i.e., months) at a number of points along a river, a simple, inexpensive (<US$40) differential voltage amplifier circuit was developed to provide an interface between a galvanic DO probe and a miniature data logger. The circuit is designed around precision, micropower, single-voltage supply operational amplifiers and consumes less than 3 W while isolating and amplifying the output of a galvanic DO probe. The circuit is efficient and rapid enough to be powered by the data logger's 2.5-V, 1-mA, 18-ms-read sensor trigger signal. The complete unit, including the enclosure and floats, was constructed for less than $700. Fourteen were deployed in the upper portion of the St. Johns River, Florida, over an 18-month period. The units remained continuously deployed for 4- to 6-month periods 82% of the time, and 93% of the collected data passed quality assurance tests.
摘要
溶解氧(DO)濃度是一個動態(tài)的水質(zhì)變量,對漁業(yè)而言非常關(guān)鍵。按照15分鐘的時間間隔,在某一數(shù)量的點,沿河流布置,長周期(幾個月)運行。一種簡單,廉價的差動電壓放大器電路的開發(fā),提供一個DO探頭和一個微型的數(shù)據(jù)之間的接口同時進行數(shù)據(jù)記錄儀。該電路的設(shè)計是圍繞精密,微功耗,單電源運算放大器,功耗小于3瓦,而隔離和放大電流的輸出DO探頭。電路是有效的,并足夠迅速由數(shù)據(jù)記錄器獲得2.5-V,1-毫安,18毫秒的讀傳感器的觸發(fā)信號。完整的單元,包括外殼,構(gòu)建了不到700 $。部署在圣約翰河,佛羅里達州的上部,在18個月內(nèi)。單位仍然連續(xù)部署4-至6個月的時間段的82%的時間,并通過質(zhì)量保證測試所收集的數(shù)據(jù)的93%。