ISO 26603-2017 pdf free download

ISO 26603-2017 pdf free download.Plastics Aromatic isocyanates for use in the production of polyurethanes Determination of total chlorine
Plastiques — Isocyanates arornatiques utilisés pour la production de polyuréthannes — Dosage du chiore total.
7.3.1 Make certain that the bomb, oxygen lines, and fittings are free of oil and grease.
WARNING — Small quantities of either oil or grease may cause a violent explosion.
When the bomb is used repeatedly, a film may form on its inner surface. Remove this film by rotating the bomb on a lathe at about 300 r/min and polishing the inside surface with Grit No. 2/0 or equivalent paper coated with light machine oil, then with a paste made from grit-free chromic oxide and water. This procedure will remove all but very deep pits while polishing the surface. Before using the bomb, wash it with soap and water to remove residual cutting oil or paste. Bombs with pitted surfaces should not be used because they will retain chlorine from sample to sample.
7.3.2 Weigh a 0.9 g sample by difference to ±0,000 5 g into the combustion capsule. WARNING — A severe safety hazard exists If more than 1 g of sample Is used.
7.3.3 Fit a 100 mm, iron-nickel fuse wire (ZZ3) onto the two electrodes. Place the combustion capsule on the ioop electrode and adjust the fuse wire in the capsule so that it is under the surface of the sample but does not touch the capsule. Place about 5 ml of Na2CO3 solution (LLZ) in the bomb and, with a small rubber spatula, wet the interior surface of the bomb, including the head, as thoroughly as possible. Put the bomb head in the bomb cylinder and the contact ring on top of the bomb head, screwing the cap down finger-tight. Close the outlet valve securely with the special wrench provided and open the main oxygen cylinder slightly. Place the bomb in its bench-mounted holder and tighten the holder with a suitably sized hex wrench. Attach the union on the oxygen-filling connection to the inlet valve of the bomb. Admit oxygen slowly (to prevent blowing the sample from the cup) to 20 to 25 atmospheres (2,03 MPa to 2,53 MPa). Close the operating valve of the oxygen cylinder and observe the pressure on the bomb gage. if a leak is indicated by a gradual pressure drop, inspect and tighten all connections. Do not continue with the test until the leak is stopped and the bomb holds pressure. Release the pressure from the oxygen tank and disconnect the bomb. Place the valve thumb nut on the oxygen inlet valve and tighten finger-tight.
WARNING — Exercise extreme caution from this point on until the bomb has been fired, cooled, and bled free of oxygen.ISO 26603-2017 pdf free download.