Development of a dual infrared and visible near-infrared measurement system for the observation of adiabatic shear bands

This paper presents the development of a new system designed to measure the local temperature field in adiabatic shear bands. Transient temperature fields are simultaneously recorded by using an array of 32 InSb infrared (IR) detectors and a streak camera working in visible-near infrared (VIS-NIR). Observations in IR offer a low temperature detection limit (550 K), but they are highly sensitive to uncertainties in emissivity. Observations in VIS-NIR allow for measurements only at high temperatures (>1000 K), but they are less affected by uncertainties in emissivity and present a higher temperature sensitivity. By performing simultaneous measurements, it is possible to obtain data in a large temperature range with an improved accuracy at high temperature. The different sources of error caused by uncertainties in emissivity, spatial resolution, and temporal resolution have been analyzed, and an estimation of the total measurement uncertainties of the system is given.