| 摘要 |
<p>PURPOSE:To accurately measure the moisture content of an objective substance by a method wherein an infrared comparing wavelength is taken on the side of a wavelength shorter or longer than an infrared absorption wavelength and the signal obtained based on the infrared comparing wavelength is extrapolated to correct the signal component of the infrared absorption wavelength. CONSTITUTION:The infrared rays of an infrared ray source 9 are guided to a sector 10 through a lens 8 and a quantity-of-light iris 6 and, when the sector 10 is rotated, infrared rays having an absorption wavelength and two infrared rays having a wavelength shorter than the absorption wavelength are successively applied to a substance 11 to be measured by optical filters 7a - 7c. Next, the reflected light from the substance 11 to be measured is incident on a cooling type PbS photodetector 4 through a condensing mirror 12, a reflecting mirror 2 and a filter 3 and the intensity thereof is measured. At this time, the signal processing synchronous to the rotation of the sector 10 is performed and a measuring signal ratio is operated from the value of infrared detection output having absorption and the values of two infrared detection outputs having no absorption and a moisture value is accurately calculated without receiving the effect of the fluctuation quantity of a reflection signal due to a factor other than moisture caused by the surface roughness of the substance 11 to be measured.</p> |
