Spectrum Detector Inc. has introduced spectrally flat pyroelectric joulemeters based on the wedge Trap concepts developed at the National Institute of Standards and Technology. The Trap consists of a large-area black pyroelectric detector opposite a large-area broadband mirror in a 15° wedge configuration that is designed so that 99% of the light passing through the 5-mm aperture is absorbed and measured. The spectral response from 0.25 to 13 μm is flat to 1% or better, and useful spectral range is from 0.2 to 1000 μm. Calibration uncertainty is <1%, and energy ranges from 100 nJ to 5 mJ. Available in analog and digital versions, the instruments have a modular design and interchangeable detectors.