| 摘要 |
PROBLEM TO BE SOLVED: To prevent a surface of a sight glass from being eroded even when the sight glass is exposed to wet steam of high temperature and high pressure for a long period, and to satisfactorily maintain measurement accuracy of dryness.SOLUTION: A dryness measurement apparatus 1 includes: sight glasses 31, 32 interposed in measurement sections 21, 22 of wet steam to be measured; and a dryness identification section 101 that identifies a value of dryness χ of the wet steam based on a relationship between a measurement value of intensity A or absorbance B of light transmitted through the wet steam and the dryness χ of the wet steam. The sight glasses 31, 32 have a contact surface with the wet steam, at least the contact surface being formed of sapphire glass. |
