Patent ID: 6060109
Filing Date: 2000-05-09
Classification: G01N

Abstract:
A method of controlling the deposition amount of a plating metal in a continuous line for manufacturing a vapor deposition coated steel strip, comprising the steps of;sampling a metal vapor from a guide duct which carries a metal vapor from a vapor source to a steel strip to be coated,carrying said sampled metal vapor through a takeoff pipe to a decompressed measuring chamber located outside of said guide duct, wherein a light source and a detector are provided,irradiating said sampled metal vapor with a measuring beam emitted from said light source,detecting said measuring beam after the irradiation by said detector so as to detect a value of absorbance of luminous energy in said sampled metal vapor,calculating a flow amount of said metal vapor passing through said guide duct from the detected value of absorbance, andcontrolling an opening ratio of a shutter provided in said guide duct on the basis of the calculation result so as to control the flow amount of the metal vapor passing through said guide duct.