LED luminaires and luminaires for discharge lamps – the usage however is decreasing – are predominantly used for technical lighting due to energy reasons. High-pressure discharge lamps are either high-pressure mercury vapour lamps, metal halide lamps or high-pressure sodium vapour lamps.
High-pressure discharge lamps
High-pressure mercury vapour lamps have not been used indoors due to their low colour rendering quality (colour rendering index ≤ 70). Since April 2015, putting these lamps into circulation has been prohibited in Europe according to Commission Regulation (EC) no. 245/2009  of 18 March 2009 (ecodesign directive – see also chapter “Environmentally sound product design”). They have been almost completely replaced by the more efficient metal halide lamps.
High-pressure sodium vapour lamps are characterised by their high luminous efficacy. Therefore, they were traditionally used for outdoor lighting and in high halls, for example in the steel industry where their suboptimal colour rendering can be tolerated. By using LED luminaires, the disadvantage of poor colour rendering can be avoided.
In general, high-pressure lamps need an ignitor, which generates the high ignition voltage, in addition to the control gear unit. In some cases, it is also generated by the electronic control gear unit.