Ratio temperature method can avoid difficulties of correction of target emissivity in temperature measurement, which enables simultaneous measurement of temperature distribution of targets having different emissivity, for example, melting and solidifying process of metal. We have studied ratio temperature method using two wavelength images captured by either a color high-speed camera or a twoimage- sensor camera. The minimum temperature limit which can be measured with a color high-speed camera is about 900 degrees centigrade, because the camera can only capture visible wavelengths. The technique for measuring temperature distribution less than 900 degrees centigrade at high-speed using single sensor camera hasn't been established. In late years, a multi-spectrum camera become commercially available, with which multiple wavelengths images can be captured simultaneously by utilizing pixel-bypixel band pass filters. If we apply this technique to sensors with high-speed capability, and with near infrared wavelength bandpass filters, temperature measurement down to 500 degrees centigrade would be possible. In this study, we report the result of temperature distribution measurements by ratio temperature method using a commercially available multi-spectrum camera which captures four wavelengths images in near infrared.

Date Published: 28 January 2019
PDF: 6 pages
Proc. SPIE 11051, 32nd International Congress on High-Speed Imaging and Photonics, 110510R (28 January 2019); doi: 10.1117/12.2527710

Published in SPIE Proceedings Vol. 11051:
32nd International Congress on High-Speed Imaging and Photonics
Michel Versluis; Eleanor Stride, Editor(s)