Patent ID: 8991240
Filing Date: 2015-03-31
Classification: G01N

Abstract:
1. A method of measuring basis weight and moisture amount for calculating a basis weight and a moisture amount of a sample constituted by a paper sheet using a microwave resonator, the method comprising the steps S 1 to S 6 of; (Step S obtaining a resonance frequency and a resonance peak level of the microwave resonator in a case without a sample; (Step S obtaining a resonance frequency and a resonance peak level of the microwave resonator in the case where the sample is measured; (Step S obtaining a resonance frequency shift amount Δf as a difference between the resonance frequency obtained in the step S (Step S obtaining a peak level change amount ΔP as a difference between the resonance peak level obtained in the step S (Step S obtaining V (Step S obtaining an absolute dry basis weight and a moisture amount using expressions: wherein V V Kf: a proportional constant for matching dimensions; Kp: a proportional constant for matching dimensions; ∈′1: a dielectric constant of the absolute dry paper−1; ∈′2: a dielectric constant of the water; ∈″1: a dielectric loss factor of the absolute dry paper; ∈″2: a dielectric loss factor of the water; and β, γ: proportional constants, and the constants Kf, Kp, ∈′1, ∈′2, ∈″1, and ∈″2 are determined through the following steps A and B, and the constants β and γ are previously determined: (Step A) for each of a plurality of standard samples having different values for one of the basis weight and the moisture amount, measuring the resonance frequency shift amount Δf and the peak level change amount ΔP by a measurement apparatus using the microwave resonator through the steps S (Step B) obtaining ∈′1, ∈′2, ∈″1, and ∈″2 when variance values of Kf and Kp are smaller than a predetermined value in the relation of the expressions (3) and (4), by taking V