A versatile near infrared imaging spectrometer

This paper presents a method for measuring spectral volumes (x, y, lambda) using a scanning approach utilising inexpensive components and assesses the performance of an instrument based on the technique described. The system uses a diffraction grating for spectral dispersion, a slit scanning system for spatial resolution and a CCD detector to allow images of samples to be examined in different wavebands, The system described has a spectral range of 650 nm to 1100 nm at a resolution of better than 5 nm, The image size is 150 x 242 pixels and an interchangeable imaging lens enables investigation of samples at different scales. With a 58 mm camera lens objects up to 50 mm x 50 mm may be imaged at a spatial resolution of up to 2 line-pairs per millimetre (0.5 millimetre). Spectral reflection images of kiwifruit are shown as an example application of the instrument.