Abstract: A handheld device for infrared reflectance measurements of samples for identification of the sample materials is a self-contained portable unit built into a handheld housing. The housing includes a window and optics on a bench adjacent the window, so that the optics will be aligned with the sample when the device is placed directly against the sample. The optics include a broad-band IR light source (ordinary lamp) shining onto an acousto-optic tunable filter (AOTF), which passes narrow-band IR light with a swept frequency; a lens focussing the IR through the window onto the sample; and a reflectance detector aligned with the window of the housing to pick up reflected light. A computer, which may be mounted in the housing, compares the detected reflectance spectrum with stored sample data spectra, and identifies the material or the components of the material and their proportions.