| 摘要 |
<p>PURPOSE:To enable accurate measurement up to the end of a paper without a filter for separation of a measuring light and a comparing light individually, by using light transmitted through a sheet-like object with multiple reflection of light between reflection mirrors of a spherical etalon. CONSTITUTION:Light from a white light source 4 is made parallel with a lens 5 and after turned to interrupted light with a chopper wheel 6, is made to irradiate a paper 3 through an irradiation window 7. Here, when a spherical mirror 19b is vibrated cyclically with a vibrator 20, light containing a resonance wavelength of 1.94mum and 1.8mum is radiated from a spherical etalon 19. Light with a wavelength band containing a measuring light M and a comparing light R is transmitted through a band pass filter 22 to be inputted into a light receiving element 14. A measuring light signal and a comparing light signal are detected with sample holding circuits 24 and 25 by a sampling pulse from a pulse generation circuit 23 synchronizing a drive signal of the vibrator 20 and thus, an arithmetic device 18 computes M/R to measure the quantity of moisture, thickness and the like.</p> |
