1.1Product definition This standard contains the initial, start of life dimensional, optical, mechanical and environmental performance requirements which a terminated and assembled single mode resilient alignment sleeve MU-PC simplex connector set (plug/adaptor/plug), adaptor and patchcord must meet in order for it to be categorised as an EN standard product. Since different variants and grades of performance are permitted, product marking details are given in 3.5. 1.2Intermateability Although all products conforming to the requirements of this standard will intermate, the resulting level of random attenuation performance will only be ensured in accordance with Table 1. The intention is that this will be true irrespective of the manufacturing source(s) of the product. 1.3Operating environment The tests selected combined with the severities and durations are representative of a category C environment as defined in EN 61753-1. 1.4Reliability Whilst the anticipated service life expectancy of the product in this environment is 20 years, compliance with this standard does not guarantee the reliability of the product. This should be predicted using a recognised reliability assessment programme. 1.5Quality assurance Compliance with this standard does not guarantee the manufacturing consistency of the product. This should be maintained using a recognised quality assurance programme. When intermating plug variants having different attenuation grades, the resulting level of attenuation can not be assured to be any better than the worst attenuation grade. The intermating of a grade C plug with a grade B plug will result in an uncertain level of random attenuation performance.