Real-time multispectral high-temperature measurement: application to control in the industry

Abstract

Many devices are used to realize non-contact temperature measurements. Whenever the body to be controlled behaves as a black body, all the devices inferring the temperature from the body radiation are accurate and reliable. On the other hand, when the body exhibits a behavior different from the black body, emissivity compensation has to be done. In case of a known emissivity, the mono-wavelength system (spectral system) is mainly used. However, when the body under examination radiates as a gray body a bicolor system is more likely to be used. In our case, we present a real time multispectral imaging system based on two CCD cameras. The system is herein presented, characterized and applications such as vision control system are presented. In the present case, two CCD, which function transfer are different due to a carefully selected set of filters, acquire data in two different wavelength ranges. This system has the advantage of providing an accurate temperature measurement as well as to display it in real time.