ISO 8769:2016 pdf free download.Reference sources Calibration of surface contamination monitors Alpha-, beta- and photon emitters Sources (le reference — Etulonnuge des contrôleurs (le contuminution (le suifuce — Emetteurs alpha, beta et photoniques. The uniformity of a Class 1 reference source minus its relative standard uncertainty shall he greater than 90 %. For the purpose of specifying the uniformity of a source with respect to surface emission rate per area, the source shall be considered as comprising a numbei’ of portions of equal area and shape. For rectangular sources, the shape of the portions shall he identical to the shape of the active area of the source. The area of the portions shall he 10 cm2 or less. For the recommended sizes (see 5.2.1), a reference source active area ot 10 cm x 10 cm shall he divided into 16 quadratic portions and a source of 10 cm x 15 cm shall be divided into 16 rectangular portions. The individual emission rates shall be determined with a relative uncertainty that shall be consistent with that specified for the whole sout-ce in 52.2 and 53..2. These uncertainties shall be taken into account when calculating the expei’imental standard deviation to determine the…