The use of thermal imaging cameras for surveillance has increased significantly over the last three to five years as pricing has dropped. The benefits are significant, whether used to augment or replace traditional CCTV systems. This is driving organisations across many industries including commercial facilities to residential housing estates, mining operations and utility and industrial sector companies, to invest in thermal imaging technologies for security and threat detection, maintenance and many other uses.
How does thermal imaging work?
Unlike standard CCTV cameras that rely on reflected visible light to produce images, thermal imaging cameras use infrared to create images based on heat emitted by natural or inanimate objects. Infrared cameras literally allow us to see in the dark and through atmospheric obscurants such as smoke, dust or bad weather. Another advantage is the reach of these devices, with high-end solutions ranging up to 4 km for un-cooled detector type cameras and up to 28 km for cooled type cameras. Intelligent imaging analytics help eliminate false alarming, the maintenance and lifecycle costs of devices are low, and these solutions are built using open systems that allow integration into the majority of CCTV systems and security platforms. The detector mean time between Failures (MTBF) is guaranteed up to 10 years for un-cooled cameras, whereas MTBF for the cooled cameras is around 10 000 hours due to the cooler construction.
Who is using thermal imaging?
Thermal imaging is being applied commercially for surveillance and threat detection with an emphasis on preventative measures rather than recognition purposes. These cameras are especially useful for perimeter surveillance, but also for preventative maintenance on critical and high value machinery and equipment, and to improve safety.
At housing estates, where extensive perimeters may border on natural or built up areas, they are particularly useful for intrusion detection. They are most often used in conjunction with standard CCTV implementations to help eliminate false alarming and to bolster intrusion detection capabilities at night or in low visibility conditions. A recent implementation at a housing estate saw the client use 30 thermal imaging cameras to secure a 13 km perimeter, replacing approximately 150 standard CCTV cameras. Together with a fibre optic cable to ensure connectivity, the implementation cost approximately R3.5 million.
In industrial and mining applications, thermal imaging is used to bolster standard security (i.e., intrusion detection) but also to identify hot spots on equipment that may indicate a need for maintenance, and to improve safety through, for example, identification of movement of people and equipment when there is low visibility. In a recent implementation at a mine, a single infrared camera placed every 600 m replaces 13 standard CCTV cameras. These cameras are also being mounted on vehicles moving inside the mine.
Thermal imaging is even being used to prevent rhino poaching. Attached to airborne drones, infrared cameras help scan vast areas, identifying poachers.
Return on investment
There are a number of benefits that offset the initial cost of thermal imaging equipment. Unit for unit, thermal imaging equipment is about 30-50% higher than the cost of standard equipment. However, over the long term, the cost of ownership of thermal imaging systems is about 25 percent that of standard CCTV systems. Lenses are more durable and do not require constant cleaning. And with no requirement for additional lighting or infrared illumination, there are savings to be had in terms of implementation. There is the added eco-benefit of no light pollution.
As with any technological solution, however, to get the expected return on investment the devices need to have the correct features.
Use a reputable brand that offers a warranty and pay attention to the details. The use of image analytics is a key area of failure – you don’t want alarms sounding every time a rabbit is sighted and you want to be able to distinguish between an antelope and a human threat. While some devices come with built-in analytics, others make use of third-party software. As many of the analytics solutions are weak, it is worthwhile ensuring a suitable solution is used.
For thermal imaging solutions that are used outdoors, a lens that can handle direct sunlight is essential. There is also the matter of image quality. Thermal imaging solutions offer 140, 320 and 640 dpi ranges. Where image quality is important, a higher spec solution is appropriate. A distinction should be made between the capabilities of cooled and uncooled cameras. On applications that require analysis of close temperature spans, the cooled camera is the preferred instrument, while the uncooled camera with its long-wave operation is less affected by solar radiation and is therefore more suited to outside work.
An experienced service provider will be able to guide you in your selection of solutions. Find a company with a proven track record that understands the challenges your facility or organisation may face. It is certainly worth the investment.
© Technews Publishing (Pty) Ltd | All Rights Reserved