Flir high-resolution camera picks out the hot spots

23 Jul 2007

Remote control and high resolution allow close monitoring of steel emerging from the furnace.

The camera

Engineers from Corus are using the new Flir ThermaCAM SC640 thermal imaging camera to monitor the temperature of rolled steel at any point from its emergence from the furnace, at roughly 1300ºC, to the final cold product.

The SC640's focal plane array has 307,200 pixels, compared with the 76,000 found in a standard imaging system, enabling the steel to be examined in greater detail. "The image quality lets us pick out the temperature of particular parts of the sections as they cool," said Chris Oswin of Corus. "With our previous camera we had to rely on an average temperature reading."

Temperature is a key factor during the steel rolling process, for several reasons. Too cold a material increases the loads and torque generated during rolling and can cause damage to the expensive equipment. Furthermore, the final properties of the steel are influenced by both the temperature at the end of the rolling process, and the rate at which the steel cools.

The large field of view of the SC640 has proved useful to the Corus team when comparing the cooling of multiple sections in close proximity to one another. "In the past we took an image of each section and compared the temperature of two or more images," explained Oswin. "Now we can get multiple sections on one image and make direct comparisons."

An 8x digital zoom facility enhances the study of smaller targets. After zooming, the camera operator can pan around the LCD display to examine all areas of the image, not just the center.

Hot metal

The camera's remote control mode and ability to be controlled by a laptop via a Firewire connection is important from a health and safety standpoint, allowing users to study the thermal performance of hot steel from a safe distance.

Flir manufactures its own lenses, allowing the development of high-precision germanium lenses designed to take full advantage of the SC640's high resolution focal plane array. A range of lenses is available, including 12º, 25º, 45º and a 50 micron microscope lens.

"We can look closely at transient processes, which we were unable to do before," said Oswin. "The ThermaCAM is smaller, lighter, easier to use and has a better battery life, so we can use it for longer periods of time and for tasks for which previous cameras were too wieldy."