BS EN ISO 11665-1:2015

1   Scope This part of ISO 11665 outlines guidance for measuring radon-222  activity concentration and the potential alpha energy concentration of its short-lived decay products in the air. The measurement methods fall into three categories:

a)
spot measurement methods;

b)
continuous measurement methods;

c)
integrated measurement methods.

This part of [ISO 11665](/search?q=ISO%C2%A011665) provides several methods commonly used for measuring radon-222 and its short-lived
  decay products in air. 
This part of [ISO 11665](/search?q=ISO%C2%A011665) also provides guidance on the determination of the inherent uncertainty linked to
  the measurement methods described in its different parts.