| 摘要 |
<p>The present invention provides a method for measuring unit area weights in material combinations having a base material, a precoat therein and at least one surface coat which method comprises irradiating the material combination with X-rays which excite the characteristic X-ray radiation of a substance in the precoat, the intensity of which is measured both above and below the coated base material, the absorption in the material combination of the primary radiation from the radiation source is measured and calculated from the mutually independent results of the unit area weights of the different coats of measurement obtained.</p> |
