| 摘要 |
A non-contact sensor system and method for determining paper sheet quality parameters such as caliper, basis weight and sheet moisture based on THz radiation are provided. The method comprises: Emitting, by an emitter system 10, a THz radiation signal 60 towards the paper sheet material 2 such that the THz radiation interacts with the paper sheet material; Detecting, by a detector system 20, a time and/or frequency dependent response 74 of the THz radiation signal 70 having interacted with the paper sheet material 2; Determining model parameters of a physical model by optimizing the model parameters such that a predicted response of the physical model is fitted to the detected response, the model parameters being indicative of transmission and/or reflection coefficients at interfaces of the paper sheet material with surrounding media; and determining, from the determined model parameters, at least some of the paper sheet quality parameters 91. |
