APPARATUS AND METHOD FOR MEASURING PROPERTIES OF AN OBJECT USING SCATTERED ELECTROMAGNETIC RADIATION

• Main Author: LOWITZ, DAVID A
• Format: Patent
• Language: English
• Published: 24.07.1991
• Edition: 5
• Subjects: CIGARETTES; CIGARS; GAMMA RAY OR X-RAY MICROSCOPES; HUMAN NECESSITIES; INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; IRRADIATION DEVICES; MACHINES FOR MAKING CIGARS OR CIGARETTES; MEASURING; NUCLEAR ENGINEERING; NUCLEAR PHYSICS; PHYSICS; SMOKERS' REQUISITES; TECHNIQUES FOR HANDLING PARTICLES OR IONISING RADIATION NOTOTHERWISE PROVIDED FOR; TESTING; TOBACCO

A method and apparatus for monitoring two components of an object, such as moisture content and density in a tobacco rod, using scattered electromagnetic radiation are provided. Both the real and imaginary parts of the dielectric constant of water vary greatly over frequencies in the gigahertz region while those of the remaining constituents of tobacco do not. At frequencies approaching 100 GHz, the real part of the dielectric constant of water is much closer to that of many organic polymers, such as those making up tobacco, than it is at lower frequencies. At frequencies approaching 100GHz the imaginary part is much lower than it is is in the region of 20 to 30 GHz. By comparing the scattering of electromagnetic radiation by a cigarette rod at two different frequencies and using a predetermined calibration curve based on a cigarette rod having a desired moisture content and density, one can determine the moisture content and density of the cigarette rod. If the monitoring is taking place on a cigarette making machine and the moisture content and density deviate from their desired values, the machine feeds can be adjusted automatically to restore the desired moisture content and density.