This part of ISO 7503 applies to the evaluation of contamination on surfaces of equipment and facilities, containers of radioactive materials and sealed sources in terms of activity per unit area. This part of ISO 7503 does not apply to the evaluation of contamination of the skin and of clothing. It applies to beta-emitters the maximum beta energy, Eβmax, of which is greater than 0,15 MeV and alpha-emitters. It is restricted to beta- and alpha-emitters, the production rate of which, with regard to beta-particles plus monoenergetic electrons and alpha-particles respectively, is near to 100 particles per 100 decays (see table 3 in the annex). For the purposes of this part of ISO 7503 the term "beta energy" refers to maximum beta energy. NOTE — Evaluation of tritium surface contamination is dealt with in ISO 7503-2. Other radionuclides of practical importance (for example electron capture and isomeric transition emitters) will be dealt with in a future International Standard.