Dust resistance
2.7.7.3.1. The retractor shall be placed in a test chamber, as shown in Annex VI. Its relative position shall be the same as that in which it is mounted in the vehicle. The test chamber shall contain a quantity of dust which meets the requirements of 2.7.7.3.2. 500 mm of the strap shall be extracted from the retractor and kept extracted, except that it shall be subjected to 10 complete cycles of retraction and withdrawal within one or two minutes after each agitation of the dust. For a period of five hours, the dust shall be agitated every 20 minutes for five seconds by compressed air which is dry and free of lubricating oil, passing through an aperture 1,5 more or less 0,1 mm in diameter at a gauge pressure of 5,5 by 10 5 more or less 0,5 by 10 5 pa.
