emphasised that sediments, if any, should always be regarded as belonging to the particular consignment involved.
With many products it is the practice to defer commencement of discharge until analysis of the samples has been completed. If the receivers indicate that the cargo does not conform to the required specification, the master should immediately request the local UK Club correspondent to arrange for the attendance of an independent surveyor and for the analysis of loading samples.
Sampling procedures
Because of the wide variety of liquid cargoes carried and the different methods of loading only general advice on sampling can be given.
Cargo sampling is a difficult process and one that requires most careful attention. It should be emphasised that each sample must be representative of the product concerned. Continuous sampling at the ship’s manifold in order to obtain a so-called ‘ship’s rail composite’ sample, though a time consuming procedure, may be of value in the case of homogeneous cargoes where tank samples taken prior to commencement of discharge have shown the product to be satisfactory at the time the ship arrived. A sample of the first cargo arriving at the ship’s manifold, a ‘first run’ sample from the ship’s tank and a sample or set of samples drawn from the tank on completion of loading are the most important. In the chemical (parcel) trade, running samples during the first
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five minutes of loading are sometimes also drawn. The object of all these sampling operations is to obtain a manageable quantity of cargo, the condition and properties of which correspond as closely as possible to the average condition and properties of the parcel being sampled.
Most liquid samples can be stored in glass jars with screw type caps or cork plugs. In most cases samples do not each have to be larger than half a litre (500cc).
The importance of cleanliness cannot be too strongly stressed. All sampling work should be done with clean hands and where protective clothing is necessary, as in the case of toxic products, clean gloves of a suitable material should be used. The apparatus used should be of a suitable material, e.g. stainless steel, which does not react chemically with the cargo being sampled. Various types of sampling bottle can be used, particularly in large tanks but should glass bottles be employed, great care should be taken to avoid breakage.
With edible oils, where smell and flavour is important in quality assessment, scrupulous cleanliness is essential and the sampling devices should be thoroughly washed with hot water and soap and rinsed with hot water before use. All sampling equipment should be protected from the weather, rain, dust, rust, grease, etc., and before the sample is divided into suitable glass jars, the outside of the sampling apparatus should be wiped clean.
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