Secchi disk, divided

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Secchi disk, divided
Secchi disk, divided in four segments, two of those black, diam. 250 mm

For  determining  the  depth  of  visibility  and  light  permeability  of  water.  This  new  sturdy  design  is  made  of  strong,  hard-wearing  plastic  and  has  a  lead  weight  for  better  lowering. The approx. 15 cm high rod is fitted with an eyelet for fastening the lowering engine. The lowering line is marked at intervals of 50 cm for better reading of the depth of visibility while the disk is being lowered.