A device for monitoring and controlling water disinfecting systems having at least one broadband UV emitter arranged in a channel, wherein the device has at least one sensor, which is arranged in the water at a distance from the broadband UV emitter, and wherein the sensor is connected to a control unit, which is set up to control the output of the broadband UV emitter or the volumetric flow of water through the channel, wherein the sensor has a maximum sensitivity to UV radiation in a wavelength range between 200 nm and 240 nm.
