Hydrowire sampler

Laboratories sampling/ Hydrowires Samplers analytical precisions... 

The method of intercomparison of the various devices was to deploy pairs of sampler types on different hydrowires to collect water samples from a homogeneous body of deep water at Ocean Station S (Panulirus Station) near Bermuda (Fig. 1.1). The water at this depth has characteristics of 3.97 0.05 °C... 

Numbers result from common computer analyses and not all such figures will be necessarily significant PCS = Plastic-coated steel hydrowire SS = Stainless steel (type 302 unlubricated) hydrowire KEV = Kevlar hydrowire HB = Hydro-bios sampler MGF = Modified GO-FLO sampler Mod GF = Unmodified GO-FLO sampler Exw GF = Unmodified GO-FLO sampler NIS = Modified Niskin sampler m = mean sd = standard deviation... 

The experiment reveals that the differences between results obtained through the use of various combinations of hydrowires and samplers are not large, and in no case can they account for the recent decline in the ocean... 

A Teflon-coated sampler (General Oceanics, 10-L Go-Flo) on a stainless steel hydrowire was used to obtain whole-water samples and samples for filtration from 16 points in the water column on each cruise. Samples were pressure filtered onboard ship, within a Class-100 laminar flow enclosure, in an all-Teflon column-filter holder (Savilex) through tared 0.4-pm track-etched filters (Nuclepore). Samples, both total P and total filtrable P, were acidified with high-purity HC1 (Ultrex) and immediately frozen. 

At the sampling step, contamination from sampling bottles and hydrowire should be minimized [10], Old types of sampling devices such as Nansen and Knudsen are constructed mostly from brass, which may cause contamination of Cu and Zn into seawater. The recently developed Niskin plastic sampling bottle provides less contamination from the sampler walls. However, the materials used for the end-caps or springs, rubber or Teflon-coated stainless steel, sometimes release significant amounts of Ba, Cu, Sb and Zn [14]. 

Immediately upon return to the ship, the hydrocast was initiated with the closed PVC sampler (containing the surface water collection) placed as the flrst bottle on the hydrowire followed by four open and cocked samplers set at various depths from 25 to 750 m. The hydrocast and sample handling were then carried out in the usual fashion. 

Serial samplers as part of a sampling system (plus winch, hydrowire, bottom weight) used from ships, optionally supplied with reversing thermometers, triggered by messengers ... 

In addition to appropriate samplers, components of an optimum sampling system for trace element studies involve plastic (coated) wires , such as made of Kevlar, or plastic coated hydrowires, serial winches with plastic drums and plastic-coated bottom weights and messengers. 

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