Spectrum Detector Inc. has released the four-page brochure “Detector Instruments for Radiometry and Optical Power Measurement,” which describes the SPI-D-50 pyroelectric, SSI-D-55 silicon and SGI-D-55 germanium modular digital detector instruments. It notes that the devices consist of three basic parts: a detector module, a USB power supply/processor and an optical front end that enables interchangeable accessories to be added. The optical front end and the power supply can be used with any of the modules. Sections and screen shots detail the single- and dual-channel LabView applications software that is included with the instruments. The SXI-D USB drivers also are discussed. Charts and diagrams are provided.