In-situ Monitoring of Powder Density Using Terahertz Pulsed Imaging

Abstract

We have developed an approach to investigate density variations in a moving powder bed by means of terahertz pulsed imaging. Terahertz measurements were acquired continuously during the rotation of a container filled with different grades of lactose and microcrystalline cellulose powder. Relative density distributions were resolved for different compaction stages of the powder, which indicated high variations of the powder density.

A Comprehensive Review on Food Applications of Terahertz Spectroscopy and Imaging

“…THz applications include security screening (García‐rial et al., ; Kaltenecker et al., ; (Liu, Zhong, Karpowicz, Chen, & Zhang, ), astronomical studies (Leisawitz et al., ), communication (Akyildiz, Miquel, & Han, ; Ergün & Sönmez, , nondestructive testing (Probst, Scheller, & Koch, ; Rutz, Koch, Khare, & Moneke, ), medical imaging (Bowman et al., ; Chavez, Bowman, Wu, Bailey, & El‐Shenawee, ; Dougherty et al., ; Fitzgerald et al., ; Sun et al., ; Truong, Fitzgerald, Fan, & Wallace, ), imaging of dental caries (Karagoz, Altan, & Kamburoglu, ; Ripoche, Reynard, Narcisse, & Roberts, ), pharmaceuticals (Markl, Dong, Li, & Zeitler, ; Pei et al., ; Sibik & Zeitler, ; Warnecke et al., , agricultural products (Liu et al., ; Liu, Liu, Hu, Yang, & Zheng, ; Luo, Zhu, Xu, & Cui, ; Nie, Qu, Lin, Dong, & He, ; Ogawa et al., ; Qin, Li, Chen, & Chen, ), food inspection and quality control (Ge, Jiang, Lian, & Zhang, ; Huang et al., , Shin, Choi, & Ok, ; Ok, Park, Kim, Chun, & Choi, ; Ok, Park, Lim, Jang, & Choi, ; Wang, Sun, & Pu, ; Yan, Liu, Qu, & Liu, ), environmental monitoring (Bigourd et al., ), and biosensing and label‐free monitoring of various biological processes (Yang et al., ). Full body THz scanners are installed in many airport checkpoints for detection of concealed objects and explosives.…”

“…. Narcisse, & Roberts, 2018), pharmaceuticals (Markl, Dong, Li, & Zeitler, 2018;Pei et al, 2018;Sibik & Zeitler, 2015;Warnecke et al, 2019, agricultural products (Liu et al, 2018Liu, Liu, Hu, Yang, & Zheng, 2016;Luo, Zhu, Xu, & Cui, 2019;Nie, Qu, Lin, Dong, & He, 2017;Ogawa et al, 2006;, food inspection and quality control Huang et al, 2015, Shin, Choi, & Ok, 2018Ok, Park, Kim, Chun, & Choi, 2014;Ok, Park, Lim, Jang, & Choi, 2018;Wang, Sun, & Pu, 2017;Yan, Liu, Qu, & Liu, 2018), environmental monitoring (Bigourd et al, 2006), and biosensing and label-free monitoring of various biological processes . Full body THz scanners are installed in many airport checkpoints for detection of concealed objects and explosives.…”