METHOD FOR ESTIMATING RELATIVE HUMIDITY INSIDE SEMI-SEALED STRUCTURE, METHOD FOR CORROSION PROTECTION INSIDE SEMI-SEALED STRUCTURE, AND DEVICE FOR ESTIMATING RELATIVE HUMIDITY INSIDE SEMI-SEALED STRUCTURE

PROBLEM TO BE SOLVED: To provide a method for estimating relative humidity inside a semi-sealed structure, a method for corrosion protection inside a semi-sealed structure and device for estimating relative humidity inside a semi-sealed structure, with which temperature and relative humidity inside a semi-sealed structure, for continuously changing temperature and relative humidity outside the structure, can be grasped.SOLUTION: A method for estimating relative humidity inside a semi-sealed structure comprises: a calculation process of temperature inside a structure (calculation process of temperature inside the structure) S2 in which a temperature inside a structure per unit time, which is Δt, is calculated; a calculation process of absolute humidity inside the structure (calculation process of absolute humidity inside the structure) S3 in which absolute humidity inside the structure per unit time (Δt) is calculated; and a calculation process of relative humidity inside the structure (calculation process of relative humidity inside the structure) S4 in which relative humidity inside the structure per unit time (Δt) is calculated, based on the temperature and the absolute humidity inside the structure per unit time (Δt) calculated in the calculation process of temperature inside the structure S2 and the calculation process of absolute humidity inside the structure S3. A temperature inside the structure per unit time (Δt) is calculated and then, temporal changes in the relative humidity inside the structure is estimated.