The UniformSun measuring system is based on a new development by Ingenieurbüro Mencke & Tegtmeyer GmbH. It enables simple and extremely precise measurement of the solar irradiance distribution of sun simulators. UniformSun's very high measurement rate of up to 10 000 measurements per second means it is also suitable for flashlight sun simulator (flashers) measurements. Thanks to it modular design, in which each PV cell functions as a sensor element and is separately encapsulated in a glass EVA laminate, interaction between individual measuring surfaces, for example, as a result of light coupling between neighbouring surfaces, is ruled out. In the overall design, emphasis was placed on replicating the optical characteristics of a conventional PV module in order to achieve representative results for sun simulators, where the test object influences the solar irradiance distribution. To attain the best possible measurement accuracy, each sensor element was individually calibrated by the Institute for Solar Energy Research (ISFH) in Hameln.