| 摘要 |
<p>In order to examine an object with radiation and measure the intensity of radiation used to illuminate the object, radiation is directed onto a wavelength selective mirror (31). In a first position, the mirror (31) reflects the illuminating radiation to a beam splitter (30) which passes the radiation to a detector (34). In a second position the mirror (31) directs the radiation to an object (33), radiation of the selected wavelength emanating from the object being reflected by the mirror via beam splitter (30) to the detector (34). The mirror (31) is rotated between the first and second position. In order to classify a diamond as natural or synthetic, a first signal is derived dependent upon the intensity of ultra-violet radiation transmitted by the diamond at 254 nm, and a second signal is derived dependent upon the intensity of radiation transmitted by the diamond at 365 nm and the diamond is classified as being definitely natural if the first signal is substantially greater than the second signal.</p> |
