Patent ID: 9528823
Filing Date: 2016-12-27
CPC Classification: A24C,A24D,G01B,G01N

Claim Text:
1. A method for measuring the position of sections having absorbing substances in a multi-segment filter rod of the tobacco processing industry, comprising the steps of: measuring a varying resonance frequency shift A and/or resonance line spread B during movement of the multi-segment filter rod in the longitudinal direction thereof using a microwave resonator, said microwave resonator having a field concentration in a spatial area, wherein this microwave resonator spatial area in the direction of the multi-segment filter rod is smaller than a multi-segment filter length, calculating a difference quotient ΔA of the resonance frequency shift A and/ or ΔB of the resonance line spread B, relative to the longitudinal direction, determining local extreme values of the respective difference quotients, and assigning the local extreme values as a position of a transition from a section with a higher content of absorbing substance to a section without absorbing substances, or with a lower content of absorbing substances, and vice versa, wherein difference quotient ΔA is calculated in accordance with the following formula wherein A(X 1 ) and A (X 2 ) designate the measured resonance frequency shift A at the positions X 1 and X 2 , and wherein difference quotient ΔB is calculated in accordance with the following formula wherein B(X 1 ) and B (X 2 ) designate the measured resonance line spread B at the positions X 1 and X 2 .