How is water sampled on the vessels?
Two kinds of sampling bottles are used on the vessels: Van Dorn water sampling bottles and, less frequently, Kemmerer water samplers. The idea behind these samplers is to allow water to be collected at a known depth. The Van Dorn bottles are used for sampling at various depths and the Kemmerer water sampler is used for surface water samples. What are Van Dorn water sampling bottles? The Van Dorn bottles provide a means of obtaining water samples at selected depths below the surface. It consists of an open ended clear plastic cylinder that can be attached to the hydrographic wire (the steel wire wound on the winch) and lowered to any desired depth. A deckhand operates the winch. The bottles also provide a platform to which thermometers can be attached to record the temperature of the water at the location of each Van Dorn bottle. Each end of the cylinder is fitted with a rubber cover. The Van Dorn bottle is attached to the line with the covers pulled out and twisted back and around to t
