Measurement system for metal strip production line

A metal strip production line measurement system is disclosed comprising a thermal imaging camera 8 configured to receive thermal radiation from a plurality of positions on a metal strip 10 being conveyed along a production line 1 and to generate an image based on the thermal radiation received. A temperature or emissivity calculation unit 34 is also provided within a processor 36 to determine temperature and/or emissivity for the plurality of positions which includes identifyingand subtracting a reflected component in the radiation received at the thermal imaging camera from a position on the metal strip. A property calculation unit 28 may calculate further properties such as coating thicknesses or process reaction rates. The metal strip production line 1 may comprise a plurality of rollers 12 for supporting the metal strip 10 and a plurality of heaters to heat the metal strip 10.