Multi-layer plastic bottle and preform thickness measurement using Terahertz pulses

This paper presents the use of Terahertz (THz) pulses using TeTechS' PlasThick™ terahertz sensor system for wall thickness measurement of an opaque plastic bottle. The problem addressed here is the measurement of the wall thickness and multi-layer thickness measurement of plastic bottles and preforms, using non-contact, non-invasive, and non-destructive measurement techniques. Single-cycle terahertz (THz) pulses with a THz photocurrent of about 100 nA generated by a 100 micrometer gap photoconductive antenna were used for plastic thickness measurement characterization. We demonstrate an order of 10 micrometer thickness measurement accuracy.