Research on X-ray attenuation method for non-destructive detection of lamina density variation rate (DVR) in cases
The density deviation is one of the significant factors that influences the tobacco aging and primary process. For example, the phenomena of oil loss, caking, or even carbonization takes place easily in the aging process because of the large density deviation. The compressed lamina, which has vast density deviation, is difficult to loosen in the conditioning cylinder. In this work, the x-ray attenuation method is applied to determine the lamina density deviation in some cases. The X-ray attenuation law of 13 kinds of laminas was investigated. A calibration method for the attenuation coefficient of given lamina was obtained. The comparison between X-ray attenuation method and gravimetric method indicates good agreement. The conclusions are as follows: 1. The X-ray device for determining the density deviation of laminas with good performance will be able to meet the testing requirements. 2. The calibration method was built in this work. The attenuation coefficient (Ki) and the scatter factor (B) were calculated according to calibration method. The accuracy of detection can be obviously improved by increasing the number of standard pieces of the known density. 3. The accuracy of detection is affected by the moisture of lamina, but the influence is less than the maximum relative error, and can be improved by re-calibration for given lamina.