As thermal imaging becomes a more accepted technology in industrial environments it can provide
exciting new solutions to applications that have been previously dominated by single point pyrometers.
The new development of an uncooled focal plane array thermal imager with a narrow band 3.9μm
filter and background compensation processing enables measurements in industrial furnaces to provide
temperature profiling of the product.
This paper will show why the use of a 3.9μm camera with a borescope optic is the most accurate noncontact
method for in-furnace temperature measurement. This will be done using the example of a
reheat furnace where in a controlled trial using an instrumented billet the measurement from the IR
device was shown to accurately track the thermocouple temperature during a variety of furnace