High quality lamp testers allow maintenance to be performed faster, which saves time and money. With little effort, these instruments can test lamps and ballasts for their function. Most illuminants such as fluorescent tubes or lighting strips do not even need to be disconnected from the socket. Depending on the model, probes on a telescopic rod detect the applied voltage, for example. A ladder is therefore usually not required. Integrated voltage and continuity testers determine reliable values. An existing problem can therefore be localised immediately and the appropriate action taken.