A rosette sampler is made of an assembly of 12 to 36 sampling bottles.[1] Each bottle is a volume that range from a minimum value of 1.2 L to a maximum value of 30 L.[1] All of them constitutes the rosette sampler and are clustered around a cylinder situated in the center of the assembly,[1] where there is a sensing system called Sea-Bird or CTD, that stands for "Conductivity, Temperature and Depth", although other variables can be measured by modern CTDs (e.g. water turbidity, dissolved oxygen concentration, chlorophyll concentration and pH).[2]