| 摘要 |
PURPOSE:To improve the detection precision of water content by providing a rotary plate for calibration which has an opening and mounts a sample for calibration on the optical path between a projection part and a body to be measured, and calibrating a measured value on the basis of a reference value obtained from the sample for calibration. CONSTITUTION:The rotary plate 12 for calibration that has the opening 13 and mounts on the sample 14 for calibration consisting of an interference filter which is similar to the body 1 to be measured and has an absorption band of specific wavelength and a reflecting mirror provided on its reverse surface is arranged on the optical path between the body 1 to be measured and the projection part consisting of a light source lamp 2, condenser lens 3, and filter 5. Then, the absorbance of the objective body 1 is measured through the opening 13 of a rotary disk 12 and the sample 14 for calibration is placed on the optical path by the rotation of the rotary disk 12 to obtain the reference value, on which the measured value is calibrated. |
