To provide a method capable of measuring the adhered oil content with high accuracy without needing a large volume of oil content extracting solution or a large immersion tank even when a large cleaning structure is the object.
Only a part of a structure to be cleaned is immersed in the oil content extracting solution 3 to determine the amount of the extracted oil in the extracting solution 3, and the total oil amount is calculated from the area ratio of the total surface area to the surface area of the immersed part. The whole surface of the to be cleaned is covered with cloth, the cloth is washed in the extracting solution 3, and the extracted oil content in the extracting solution 3 is determined. A part of the surface of the structure to be cleaned is wiped with a cloth 4, the cloth is washed in the extracting solution 3 to determine the extracted oil content in the extracting solution 3, and the total oil amount is calculated from the area ratio of the total surface area to the surface area of the part wiped with the cloth 4. The structure is immersed in the oil content extracting solution 3 by the part to determine the total extracted oil amount in the extracting solution 3.
YAMAGUCHI SHINOBU
HIRANO TAKASHI
HARADA KAZUO
