A spectrometer for infrared reflectance measurements of samples for
identification of the sample materials is built into a steering wheel
assembly. The spectrometer 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 in optical alignment with or 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 focusing the IR
through the window onto the sample; and a reflectance detector aligned
with the window of the spectrometer to pick up reflected light. A
computer, which may be mounted in the spectrometer, compares the detected
reflectance spectrum with stored sample data spectra, and identifies the
material or the components of the material and their proportions. When a
control substance is detected an alarm signal is produced.