Secchi disk


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Secchi disk

n.
A disk, divided into black and white quarters, used to gauge water clarity by measuring the depth at which it is no longer visible from the surface.

[After Pietro Angelo Secchi (1818-1878), Italian astronomer hired to test such a disk.]
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find that subjective measures tend to underreport water clarity compared to objective measures (such as Secchi disk readings).
TABLE 1 Minimum, averages [+ or -] Standard Deviation, and maximum values of abiotic variables, trophic state indices, and total biomass at the three collection points in the euphotic (*) and aphotic (**) zones of the Argemiro de Figueiredo reservoir (Brazil) from August/2007 to July/2009 Confluence of the tributaries rivers (PC) Min Mean [+ or -] SD Max Secchi disk (m) 0.
Zooplankton ornekleri golden secilen 5 istasyondan aylik olarak uc tekerrurlu alinmis ve istasyonlarda ornekleme sirasinda su sicakligi, cozunmus oksijen, pH, Secchi disk derinligi, elektrik iletkenligi ve su derinligi olculmustur.
Development of an empirical model for chlorophyll-a and Secchi Disk Depth estimation for a Pampean shallow lake (Argentina).
The turbidity levels are determined by the Secchi disk depth (The Secchi disk depth provides a method for assessing turbidity.
Water clarity was determined with the help of Secchi disk and turbidity with turbidity meter (Orion, AQ-4500).
1 gasoline-water mud pump arnomis- 1 2 batteries from 150 Ah to 200 - 2 3 Centrifuges - 1 Mobile Laminar 4 - 1 5 of moisture, temperature and pressure (0-100 hPa) probes - 1 of 6 rabble - extractors with accessories - 1 7 Electric range - 1 of 8 Triple filtration system with a vacuum pump - 1 9 Single filtration system with a vacuum pump - 1 10 Secchi disk - 1 of 11 samples drying unit (with the weighing function) - 1 12 Air conditioning - 1 3 public lots.
Secchi disk depth (Secchi), water surface temperature (Temp), dissolved oxygen (DO) content, and pH were measured in situ, the rest of the chemical analyses were performed at Tartu laboratory of the Estonian Environmental Research Centre.