CI Systems SR-2-33 is a high-temperature cavity blackbody radiation source used for infrared detector and spectrometer calibration, designed around a fixed 1-inch aperture. It covers a temperature range of 100–1200 °C with a 1 °C readout resolution; accuracy is specified as ±2.5 °C up to 1000 °C and ±3.0 °C above that. In the SR-2 family, the blackbody head weighs about 7 kg and the controller about 3 kg, with SR-2-33 offering no built-in communication ports in the documented variant.
