A difference between the signal from two horns was first detected by the 10 Giga Hertz Radiometer in 1992. In 1994 all three Twin Horn Receivers comprehensively detected a common signal. This made the Tenerife Experiment the first experiment to identify specific fluctuations in the Cosmic Microwave Background. These correspond to a temperature fluctuation of 30 Microkelvin in the otherwise even temperature of 2.73 Kelvin of the Cosmic Background Radiation.