Secchi disk, divided

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. more