BS 5416:1990 pdf free.Specification for China tableware.
BS 5416 The water absorption (see 2.11) of china tablewareis assessed as the increase in mass which a preparedtest piece undergoes as a result of controlled immersion in water,expressed as a percentage ofthe mass of the dry test piece.
Air-circulating oven, capable of maintaining atemperature of 110 5°℃.
Balance, capable of determining masses ofbetween 5 g and 20 g to an accuracy of 0.001 g.A.2.4 Vessel, from which air can safely be removedand in which boiling of the test pieces in water maytake place.
De-gassed distilled or de-gassed de-ionizeduaterSmooth cotton cloth.Immcdiatcly bcfore commencement of the tcstprocedure break the sample, by impact,and taketwo test pieces of between 6 g and 20 g in mass fromareas of the broken sample as follows.
a) For flatware, take one test piece from thecentral area and the second test piece from therim area of the sample.
b) For holloware, take one test piece from the topsection and the second test piece from the basearea of the sample.
Dry the test pieces to constant mass in an air-circulating oven maintained at 110 5°C.Coolthe test pieces in a desiccator (A.2.2) to ambienttemperature.weigh the test pieces and record theirmasses to the nearest 0.001 g. Flace iie iry iesi pieces into a vessei (Ai.2.4), reducethe pressure therein to 2.5士1.5 kPa and maintainat this pressure for 60  5 min.
Without admitting air, admit de-gassed distilled orde-gassed de-ionized water (A.2.6) at ambient temperature to the vessel, until the test pieces arefully covered. Then admit air to the vessel,
returning it to atmospheric pressure, and boil thewater and test pieces for 60 5 min ensuring thatthe test pieces remain fully submerged.Allow thetest pieces to cool for not less than 24 h whilstremaining submerged in the boiled water.
Remove the tcst pieces from the water and wipethem with a moistened smooth cotton cloth (A.2.7)such that glazed surfaces are completely dry andbroken surfaces retain a thin film of moistureappearing as a sheen.Weigh each test piece andrecord their masses to the nearest 0.001 g.BS 5416 pdf download.