1.1Product definitionThis standard contains the initial, start of life dimensional, optical, mechanical and environmental performance requirements which a terminated and assembled singlemode EC connector set (plug adapter plug) must meet in order for it to be categorised as an EN product specification.Since different variants and grades of performance are permitted, product marking details are given in 3.5. 1.2IntermateabilityAll 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.In all cases, the intermating of plug variants having different attenuation grades will result in an uncertain level of random attenuation performance.Similarly, the intermating of plug variants with suffix A, with plug variants with suffix C, will result in an uncertain level of random attenuation performance.1.3Operating environmentThe tests selected combined with the severities and durations are representative of an external weather protected environment defined by–ES 200 671: external weather protected environment defined by ETS 300 019-1-3 classes 3.3, 3.4 and 3.5–EN 61753-2-1 category U: uncontrolled environment.1.4ReliabilityWhilst 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 assuranceCompliance with this standard does not guarantee the manufacturing consistency of the product. This should be maintained using a recognised quality assurance programme.