A method for mass measurement per unit area, a method for manufacturing a laminated film, and a mass measuring device per unit area

摘要

The occurrence of measurement error due to film thickness variation is avoided and the mass per unit area of the coated layer of the laminated film is measured. The mass per unit area measuring device 30 includes a light emitter 31a for emitting light having a center wavelength of 405 nm, a light emitter 31b for emitting light having a center wavelength of 850 nm, A light receiver 32a and a light receiver 32b and a control unit 33 for calculating the mass per unit area of the heat resistant layer 4 based on the transmitted light intensity of each light.