ISO 13909-5:2016 pdf free download.Hard coal and coke Mechanical sampling Part 5:Coke Sampling from moving streams Houlile et coke — Echantillonnage mécanique — Partie 5: Coke — Echantillonnage en continu. Under some conditions, e.g. high ambient temperature, increments which are smaller than those corresponding to the design capacity of the system may suffer from disproportionate changes in quality, e.g. loss in moisture, and precautions need to be taken to prevent this. If such losses cannot be prevented and are found to cause bias, such means as buffer hoppers shall be used. Alternatively, increments can themselves be retained temporarily in a buffer hopper until there is sufficient mass to ensure passage, without introducing bias into the system, through an on-line preparation system. On no account shall a primary sampler be switched off at low flow rates to avoid low mass increments. When measuring primary increment variance (see ISO 13909-7:20 16, Clause 6) at preliminary stages in the design of the sampling scheme, use increment masses that are close to those expected to be taken by the system, based on similar coke from similar sampling systems. After implementation of the sampling scheme, the precision of the result can be estimated and adjusted…