Infrared Slag Detection - Theory of Operation
Physics
The property of a body to emit radiation is called its'
emissivity. The difference in emissivity between slag and steel in
the infrared range is quite large, The ITEMA system capitalizes on this
difference. Infrared sensors and cameras are able to detect the infrared
radiation emitted by solid and fluid objects. By using an infrared camera
to image the tapping stream we are able to accurate measure the emissivity and
therefore clearly detect the point at which slag is introduced into the tapping
stream.
Radiation Classes
The chart below depicts the radiance classes present during a
single tap. The blue lines represent the radiation during a full steel
stream at the beginning or middle of the tap. The red lines depict the
radiation pattern emitted when slag appears near the end of the tap. The
ITEMA system is designed to measure and analyze these differences. And due
to the camera design, the system can operate reliably in the presence of gases,
particulate matter and smoke.
