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 being conveyed along a production line 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 identifying and subtracting a reflected component in the radiation received at the thermal imaging camera from a position on the metal strip.