| 摘要 |
<p>An emission spectrophotometer has a spectrally selective cutoff mirror (17) disposed immediately in the emission path of ultraviolet lamp (16) for reflecting radiation of wavelengths shorter than 265 nm and transmitting only wavelengths longer than 265 nm. A spherical collecting mirror (20) adjacent to filter (17) collects filtered radiation from lamp (16) and focuses it on mirror (28). A first and second spectrally selective mirrors, (42) and (44) respectively, are disposed in series along the beam reflected by reducing mirror (28). Each spectral mirror reflects a beam of selected wavelengths to a corresponding solid state detector (50) and (51). The first spectrally selective mirror (42) spectrally splits the beam (18) into two beams (18a) and (18b) of different wavelengths. Reflected beam (18a) is the sample beam and is reflected to the detector (50). Wavelengths of beam (28) transmitted through spectral mirror (42) impinge on the second spectrally selective mirror (44) which reflects a different band of wavelengths, beam (18b), the interferant/reference beam, to the second detector (51). The sample signal is subtracted from the interferant/reference signal.</p> |
