Patent ID: 7423435

Claim:
A grammage measuring method for determining a grammage of a measuring sample by arranging a sample measuring surface of a dielectric resonator at only one surface side of a sample under a fixed condition, the grammage measuring method comprising the steps of: a first step of obtaining a calibration curve, which indicates a resonance frequency shift amount for a grammage, by measuring a resonance frequency shift amount of the dielectric resonator for each grammage of a standard sample, which has a known grammage, by changing the grammage while a dielectric constant and a density of the standard sample are kept constant; a second step of measuring a resonance frequency shift amount of the measuring sample, which has the same dielectric constant and density as the standard sample and has an unknown grammage, under the fixed condition with the dielectric resonator; and a third step of determining the grammage of the measuring sample from the measuring value of the second step and the calibration curve, where, the resonance frequency shift amount is a difference in resonance frequency between absence and presence of the sample (the standard sample or the measuring sample), wherein a measuring apparatus including a plurality of dielectric resonators is used, the dielectric resonators being arranged in a same first plane so that electric field vectors of the dielectric resonators having one-directional components in an in-sample second plane parallel to the first plane are different in direction from one another, resonance peak levels are detected from amplified signals of outputs from the plurality of dielectric resonators while attenuating or amplifying an output of microwave oscillation means to each of the plurality of dielectric resonators or the outputs from the plurality of dielectric resonators so that each resonance peak level is brought close to a predetermined resonance peak level, dielectric anisotropy of the measuring sample is determined from a difference in output among the plurality of dielectric resonators, and the calibration curve is determined using an average value of the outputs of the plurality of dielectric resonators, and the grammage of the measuring sample is determined from the calibration curve and measurement result based on the average value of the outputs of the plurality of dielectric resonators for the measuring sample.