BS EN ISO 307:2019 pdf free.Plastics – Polyamides – Determination of viscosity number.
Transfer 50 ml of m-cresol (5.1.3) into a weighing flask (6.4) and add with a glass pipette (6.5) 0,14 ml of orthophosphoric acid (5.1.Z). Close the flask and stir with a magnetic stirrer for 30 min at 100 °C. Add the solution to approximately 800 ml of m-cresol in a volumetric flask while continuously stirring.
Rinse the weighing flask several times with m-cresol and add this to the m-cresol solution. Remove the magnetic stirrer and dilute to the mark. Stir the solution for 30 min.Viscometer, of the suspended-level Ubbelohde type, complying with the requirements of ISO 3105. The essential dimensions of the viscometer are shown in Eigure 1. For use with the formic acid solution (5.1.2), the inside diameter of the capillary shall be 0,58 mm士2 % (complying with the requirements of size No.1 of ISO 3105). For use with the sulfuric acid solution (5.1.1) or m-cresol (5.1.3), the inside diameter of the capillary shall be 1,03 mm土2 % (complying with the requirements of size No.2 of ISO 3105]. Other types of viscometer listed in ISO 3105 may be used, provided that the results are demonstrated to be equivalent to those of the Ubbelohde viscometers specified above. In cases of dispute, the recommended viscometer shall be used. ISO 1628-1 shall be followed on selecting other type(s) of viscometer. In this document, the No.1 and No.2 Ubbelohde viscometers according to ISO 3105 are recommended. It is to be expected that at the next 5 year revision only these two viscometers will be allowed.Clean the viscometer (6.8) prior to the first use, again after discordant readings (for example, when two successive determinations of the efflux time of the solvent differ by more than 0,4 s) and, further, at intervals during regular use. For this purpose, allow it to stand for at least 12 h filled with a cleaning agent (5.2), for example chromic acid solution (5.2.1). Remove the cleaning agent, rinse the viscometer with water then with acetone (5.2.2) and dry, for example by a slow stream of filtered air or in the vacuum drying cabinet (6.1).BS EN ISO 30 pdf download.