Uncertainty Estimates for Temperature-Sensitive Paint Measurements with Charge-Coupled Device Cameras

Abstract

Temperature-sensitive paints (TSPs) have become a popular technique for the measurement of surface temperature. Consequently, uncertainty estimates are essential. Whereas TSP is similar in many respects to pressure-sensitive paint (PSP), there are some important distinctions. In particular, TSP is not sensitive to pressure, although PSP is sensitive to temperature. Therefore, a significant error source in PSP intensity measurements is absent in TSP applications. An uncertainty analysis is presented of luminescent TSP intensity measurements with charge-coupled device cameras. Elemental bias and precision error sources are described in detail, and techniques to estimate their magnitude are given for both standard-video and scientific-grade camera systems. Example applications of the technique and uncertainty analysis to swept-wing and swept-cylinder models in supersonic flow are presented. It is shown that error estimates are quite dependent on the system and test configurations. However, the relative motion between model and illumination source(s) is often the dominant error term. A technique to minimize this effect is described