For the purposes of this chapter, the following definitions shall apply
1° Radiation protection adviser: the person appointed by the employer to advise on the radiation protection of workers as referred to in Article L. 4451-2 ;
2° Extremities: hands, forearms, feet and ankles;
3° Basic nuclear installation: the basic nuclear installation defined in Article L. 593-2 of the Environment Code. For the purposes of this chapter, the secret basic nuclear installations defined in 1° of article L. 1333-15 of the Defence Code are considered to be a basic nuclear installation;
4° Reference level: the level of effective dose, equivalent dose or activity concentration above which, in a radon exposure situation or in a radiological emergency, it is deemed inappropriate to allow exposure of workers to ionising radiation, even if it is not a limit that cannot be exceeded;
5° Dose constraint: a restriction defined by the employer on a prospective basis, in terms of individual dose, used to define the options considered for optimising worker protection;
6° Operational dosimeter: electronic device for real-time measurement of the dose equivalent and its flow rate, fitted with configurable alarms;
7° Industrial radiology equipment: work equipment emitting ionising radiation used for non-medical purposes.