| 摘要 |
PCT No. PCT/GB96/02182 Sec. 371 Date Mar. 4, 1998 Sec. 102(e) Date Mar. 4, 1998 PCT Filed Sep. 5, 1996 PCT Pub. No. WO97/09605 PCT Pub. Date Mar. 13, 1997A calibration standard for use with an infrared optical absorption measurement gauge having an assembly with an optical interference filter (22) and one or more optical elements. The interference filter has spectrally selective properties so that all but a selected spectral band is reflected by the filter towards the detectors of the gauge. The transmitted band is selectively absorbed by the optical element(s) which are spectrally unselective and also directed towards the detectors of the gauge. The position and strength of the selected band can thereby be adjusted to simulate an absorption spectrum, i.e., a corresponding spectral band which is characteristic of the absorption spectrum of a material under measurement. The standard is used to calibrate the absorption measurement gauge. |
