Non-destructive evaluation of artillery combustible cartridge case using terahertz radiation

• Published in: Measurement : journal of the International Measurement Confederation 2024-06, Vol.233, p.114772, Article 114772
• Main Authors: Pałka, Norbert, Maciejewski, Marcin, Kamiński, Kamil, Powała, Dorota, Orzechowski, Andrzej, Świderski, Waldemar
• Format: Article
• Language: English
• Subjects: Combustible cartridge case; Non-destructive testing; Terahertz; Thickness measurement; Time-domain spectroscopy
• ISSN: 0263-2241; 1873-412X
• DOI: 10.1016/j.measurement.2024.114772

•Artillery combustible cartridge case scanned with terahertz radiation.•THz rotary scanner with time domain spectroscopy in reflection configuration.•Wire polariser employed as a reference for stable time difference determination.•Case radius measured with an uncertainty of 0.04 mm.•Thickness of the case wall determined with an uncertainty of 0.03 mm. In this study, terahertz radiation was employed to determine the radius, diameter, and thickness of the nitrocellulose combustible cartridge case used for tank ammunition. The construction of the sample was outlined, and the refractive index of the case material was measured. A terahertz rotary scanner with a time-domain spectroscopy setup in reflection configuration was developed, and its performance and parameters were determined. A wire polariser was introduced as a reference to determine the stable time difference. The radius and diameter measurements of the case were based on a reference terahertz pulse reflected from its metal base. The thickness of the case was calculated based on the time difference between pulses reflected from its inner and outer surfaces. These measurements were in agreement with the reference measurements. The results prove that the developed setup and measurement methods are suitable for the non-destructive evaluation of cases and provided satisfactory performance.