The Model TIR-570 Total Infrared Radiometer represents the state-of-the-art for making precise field measurements of downwelling broadband atmospheric infrared irradiance. The TIR-570 uses a advanced chopped pyroelectric detector and precision interference filter integrated with a self-contained black body source to measure spectral irradiance from 4 to 30 μm. Global climate change researchers now have a tool for routine high accuracy atmospheric IR measurements.