FLIR shows new thermal imaging camera

Published 3 May 2007

Thermal imaging is becoming more popular for security and surveillance missions, and FLIR, a thermal imaging specialist, offers a new line of low-cost passive imaging systems

Thermal imaging is the specialty of Wilsonville, Oregon-based FLIR (NASDAQ: FLIR). A few weeks ago the company released its latest contrubution to this growing sub-field of the security and surveillance industry. The new offering is the SR-Series, consisting of four infrared cameras built around uncooled infrared sensors and using composite video output. What is more, the SR-Series boasts lower price relative to comparable products, and the products may be integrated into existing CCTV systems. The system may be installed in fixed positions or on pan/tilt mechanisms for broader coverage.

The products in the new family use passive thermal imaging technology, but may, impressively, still detect intruders at a range of up to one mile. FLIR uses microbolometer infrared sensor technology which creates images out of objects’ inherent thermal signature with no need for illumination (on the differences between active and passive thermal imaging, see below).

Andy Teich, president of FLIR’s Commercial Vision Systems Division, did not mince words: “The advent of this low-cost, high performance imagers signals nothing less than a revolution in the capabilities available to all levels of the security and surveillance industry.”

There are two modes of thermal imaging — active and passive. Active thermal imaging systems use a continuous or pulsed laser or other means to raise the temperature of the target by illuminating its surface, typically over a small area at a given time. Passive thermal imaging systems sense the inherent temperature of the target. Active systems have capabilities that passive systems do not have, but passive systems are simpler and the most common. The major advantage of passive imaging is that it is more suitable for covert surveillance of wide areas.

In passive thermal imaging, the available light is used to look at a scene, which is heated or cooled by some process. It is possible, for example, to obtain the thermal image of chocolate chip cookies while they are being baked, by imaging the temperature variations induced on the product during the baking process. In an active system one is continuously monitoring a target while heating or cooling to obtain the delta temperature. For example, some automakers use active thermal imaging in car manufacturing: In one automotive application, composite body panels are glued to the frame, and the application requires creating the delta temperature by blowing warm air. The result is a guaranty that the glue line is continuous and without gaps.

The different technologies mean that active and passive systems are used for different applications: Active thermal imaging systems typically make real-time decisions based on the camera output, while passive systems generally are used as monitors.