BS ISO 719:2020 pdf free.Glass – Hydrolytic resistance of glass grains at 98 °C一Method of test and classification.
BS ISO 719 This document specifies a] a method for determining the hydrolytic resistance of glass grains at 98 °C. The resistance is measured and expressed by the volume of acid required for titration of the alkali extracted from the unit mass of glass, and can also be expressed by the amount of sodium oxide equivalent to this volume of acid, and b) a classification of glass according to the hydrolytic resistance determined by the method of this document. This document is intended for use on the less resistant types of glass, such as soda-lime glass. NOTE 1
For the more resistant glasses, e.g. borosilicate glass, the method specified in ISO 720 is more suited. NOTE 2 It is emphasized that there is no exact correlation between the classification laid down in this document and that laid down in ISO 720, and it is, therefore, essential to identify which classification is being used.The method of testing is a test for glass as a material applied on glass grains. Extraction of 2 g of grains,of particle size between 300 μm and 500 μm, with grade 2 water for 60 min at 98。C. Measurement of the degree of the hydrolytic attack by analysis of the extraction solutions.The test method shall not be applied to glasses with extreme low alkaline contents or that are essentially free of alkaline species as this method measures only the alkaline release as the indication for chemical durability.The density of the glass to be tested should, preferably, be 2,4 g/cm3土0,2 g/cm3 at 20 °C.5.1 Test water, to be prepared as follows: prepare the test water from distilled water (5.6) by multiple distillations. Remove the carbon dioxide by boiling for at least 15 min before use in a boiling flask [6.6]
of fused silica or borosilicate glass and cool. Any other suitable method may be used, e.g. preparation of carbon dioxide-free water according to USP 660[4].BS ISO 719 pdf download.