Difference between revisions of "Turbidity sensors"
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==Introduction== | ==Introduction== | ||
===Definition=== | ===Definition=== | ||
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===Measurements of Turbidity throughout history=== | ===Measurements of Turbidity throughout history=== | ||
| − | The first record of turbidity being approached in a scientific way, is attributed to the head of the Papal Navy in 1865, Commander Cialdi. Commander Cialdi was interested in the transparency of the sea and the visibility of its floor (for navigational purposes) and | + | The first record of turbidity being approached in a scientific way, is attributed to the head of the Papal Navy in 1865, Commander Cialdi. Commander Cialdi was interested in the transparency of the sea and the visibility of its floor (for navigational purposes) and during his research he had read that a captain had reported seeing a plate in a net at a depth of 40 m. Commander Cialdi commenced his investigation on the sea visibility and immediately tried several different disc sizes and colors. Later, he hired the services of Professor Pietro Angelo Secchi, an Italian scholar and priest. Together they published ''Sur la Transparence de la Mer.''(On the transparency of the Sea) where they described the development of a white disc connected to a pole or a cable to measure the transparency of the sea. Secchi made further observations on the influence of the boat's shadow, the surface reflection of the light, the clearness of the sky, and the height at which the observer stands. While his method has been used ever since and it is still used today as a qualitative measure of the oceans' turbidity, it has never been standardized and its accuracy is very limited. |
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==Turbidity Sensors== | ==Turbidity Sensors== | ||
Revision as of 13:03, 26 July 2012
Contents
Introduction
Definition
Turbidity is defined as the reduction of transparency of a liquid caused by the presence of non-dissolved suspended matter.[1] The origin of the particles found in seawater can be mineral (such as clay and silts) or organic (such as particulate organic matter or even living organisms like plankton). Turbidity is not, however, a direct measure of suspended particles in water, but a measure of the scattering effect such particles have on light.
Measurements of Turbidity throughout history
The first record of turbidity being approached in a scientific way, is attributed to the head of the Papal Navy in 1865, Commander Cialdi. Commander Cialdi was interested in the transparency of the sea and the visibility of its floor (for navigational purposes) and during his research he had read that a captain had reported seeing a plate in a net at a depth of 40 m. Commander Cialdi commenced his investigation on the sea visibility and immediately tried several different disc sizes and colors. Later, he hired the services of Professor Pietro Angelo Secchi, an Italian scholar and priest. Together they published Sur la Transparence de la Mer.(On the transparency of the Sea) where they described the development of a white disc connected to a pole or a cable to measure the transparency of the sea. Secchi made further observations on the influence of the boat's shadow, the surface reflection of the light, the clearness of the sky, and the height at which the observer stands. While his method has been used ever since and it is still used today as a qualitative measure of the oceans' turbidity, it has never been standardized and its accuracy is very limited.
Turbidity Sensors
Light Scattering
Causes and Impacts of turbidity in Marine Ecosystems
High turbidity has a number of detrimental effects on aquatic ecosystems: decrease in light penetration (limiting plant growth), fish movements and the ability of predatory fish and birds to see their prey. High turbidity means high concentration of suspended solids, which can harm fish and other aquatic fauna. These suspended solids in the process of settling down to the ocean bottom have a choking effect on bottom dwelling organisms and aquatic habitats.[2]
