*** 9411202 Stein This Small Business Innovation Research Phase II project will design and develop a two-wavelength active pyrometer. Many production and research applications require accurate, non-contact surface temperature measurements on various materials under a variety of conditions. All such surfaces emit radiation, which may be used to measure their surface temperatures, providing the surface's emissivity is known. Unfortunately, emissivity values are frequently uncertain, which can lead to large errors in conventional radiation pyrometry. This research concerns a new active pyrometer method, wherein the ratio of target reflectances at two separate wavelengths is measured together with the target radiances at these same wavelengths. From these values the surface emissivity may be determined and the target temperature accurately measured for materials having arbitrary surface textures. Research completed under a Phase I program has determined that it is feasible to construct such an instrument to cover a target temperature range of 100-1750( C with an accuracy of + 0.5% of the absolute temperature. This is perhaps an order-of-magnitude better than can be realized with conventional radiation pyrometry when the target emissivity is not known, or is changing. The new pyrometer would help producers and manufacturers in many industries to improve the quality and reduce the cost of their research, factory processes and products. Commercial applications include: production of ferrous and non-ferrous metals, semiconductors, plastics, foods, textiles, etc., where non-contacting temperature measurements are needed and conventional pyrometry is often inadequate. ***
