Within a group of units, the category defines the classification with regard to the required level of safety. The device category indicates the technical requirements placed on a device for the individual Ex zone. The categories are defined as follows:
Category 1 encompasses devices the design of which is such that they can be operated in conformity with the characteristic values specified by the manufactured and guarantee a very high degree of safety.
Category 2 encompasses devices the design of which is such that they can be operated in conformity with the characteristic values specified by the manufactured and guarantee a high degree of safety.
Category 3 encompasses devices the design of which is such that they can be operated in conformity with the characteristic values specified by the manufactured and guarantee a normal degree of safety.
