An Added Dimension

An Added Dimension

Temperature-based alarms now part of thermal cameras

Among security professionals, thermal cameras are gaining greater acceptance than ever before for their ability to detect faint heat signatures around the clock and in conditions that would blind typical video cameras.

This is especially important when guarding a perimeter. Any perimeter. It could be the fence line around a nuclear power plant, a petrochemical refinery or a remote, unmanned substation. Any and all of these facilities are vulnerable to intruders and vandals, and it’s your job to use the tools at your disposal to keep the bad guys outside the fence. This is all well known.

What many security professionals may not know is that thermal cameras have been the industry standard for monitoring what happens inside the same fence for decades. Small, handheld thermal cameras are used every day by maintenance and operations staff to do such diverse tasks as condition monitoring, predictive maintenance and critical vessel monitoring. Because these cameras are precisely calibrated, they let their users actually measure the temperature of objects all over the facility.

Take, for example, an electrical substation. From a security standpoint, you don’t want someone cutting through the fence to steal the copper or otherwise disrupt operations. An unplanned service interruption can cost the utility thousands of dollars in lost revenue and repair costs.

They have the same goal on the maintenance and operations side of the house, but they’re trying to prevent unplanned outages by inspecting thousands of components inside the fence. With their thermal cameras, workers can look at the transformers, insulators, coolers, shunts and everything else to see if any are giving off excess heat. This heat build-up could be a sign of an impending failure. If they can reroute power around the failing component and repair it without any loss of service to their customers, that’s a good day at work.

But, you may well ask, what does that have to do with you?

A Little Background…

Thermal security cameras have been the best nighttime security imaging solution for years. But the last few years have seen the cost of high-quality thermal security cameras come down dramatically, with models now being available for as little as $3,000, greatly expanding their use around the security industry. But their cost is only part of the story. Thermal security cameras have other advantages that make them worthy investments for a wide variety of installations.

Support Infrastructure

Economically, the costs involved in the design, installation, operation and upkeep of a support infrastructure of lighting towers and illuminators quickly outstrips the acquisition cost of a network of thermal security cameras. Because they’re not dependent on any visible light, thermal security cameras don’t need auxiliary lighting to work, so they can provide effective virtual perimeters for a fraction of the cost of visible-light imagers.

Conventional CCTV cameras—even ones claiming to be lowlight—need an outside source of illumination if they’re going to create an image after the sun goes down. This limits their practical utility to the range of their illumination source, which can be as little as a few hundred feet, when the tactical situation may require surveillance capability that stretches for miles. With roughly half of every day happening after the sun drops below the horizon, homes, factories and borders can be left under-secured for large portions of every day.

24/7 Video Security Coverage

Thermal security cameras let people see what their eyes cannot. Invisible heat radiation is emitted by all objects regardless of lighting conditions. Thermal cameras detect the minute temperature differences between objects and turn them into video that displays on almost any TV monitor.

Because they see heat, not light, thermal cameras are effective law enforcement tools in any environment. They can easily detect intruders and other potential hazards to the security of people and infrastructure in any weather, as well as all day and all night.

Cameras that create images based on visible light, like conventional CCTV and illuminated cameras, have the advantage of creating images that are familiar and easy to interpret. Unfortunately, the ability of a given detector—be it in an eyeball or a camera—to create these images relates directly to the amount of light available.

At night, for instance, when there isn’t much visible light to work with, we are limited to starlight, moonlight and artificial lights to help us see. If there isn’t enough light, we can’t see.

Another limitation of cameras that create images from reflected visible light is contrast. Just like the human eye, these cameras create better images if the object they are looking for has lots of contrast compared to its background. If it doesn’t, they won’t be able to see it. That’s how camouflage works; it’s essentially a way of decreasing the visible contrast between an object and its surroundings.

Thermal cameras don’t suffer from the basic limitations of visible-light imaging. First, thermal cameras make pictures from heat, not light, having nothing to do with reflected light energy. They see the heat given off by everything under the sun. Everything we encounter in daily life creates heat energy, called a “heat signature,” that thermal cameras can see clearly.

Not only does everything have a heat signature, but these heat signatures create their own contrast, so the thermal energy seen by thermal cameras generally creates a better image at night than during the day. They work just fine during the day—as long as there is the tiniest bit of temperature contrast between an object and its background, you can see it—but they work best at night.

An important tactical distinction to understand is that security operators, law enforcement officers and federal agents aren’t using thermal cameras to identify suspected criminals and terrorists. They use thermal cameras to detect the presence of people in restricted or suspect areas, assess the tactical situation, and respond accordingly. Because no one can hide their heat, thermal security cameras are the best tools officers and agents can use to know how many intruders they’re facing and, consequently, how many officers or agents should respond to meet the threat.

Recent developments in thermal imaging technology have allowed manufacturers to combine detection capability with the power of temperature measurement to create a multi-dimensional tool that covers perimeter security and operational predictive maintenance.

Electrical Substations

Many local utilities have determined that thermal security cameras provide a proven solution that helps them keep their vital facilities secure night and day.

Even essential substations—those providing power to vital infrastructure assets and local military bases—are typically unmanned; their network of fence sensors and CCTV cameras are monitored remotely from a central security facility or dispatch center.

A typical substation will install a network of thermal cameras coupled with video analytics. This combination has proven itself time and again, resulting in vastly improved situational awareness and dramatic reductions in theft-related losses.

Thermal security cameras provide clear imagery in total darkness so operators can monitor the substation’s fence lines and the surrounding area for approaching people and vehicles. Thermal video is naturally high in contrast, so it works well with video analytics packages used in the typical central monitoring facility.

Thermal cameras positioned at the corners of the perimeter provide complete coverage of the entire property. The thermal cameras are designed to produce the appropriate pixels on target for integration with the video analytic equipment. Alarms are generated based on rule violations, and the supporting video is sent to the central security control room for processing.

This combination has proven superior to using the traditional perimeter motion detection and fence alarm equipment, in some cases completely eliminating false alarms and the accompanying nuisance dispatches. A combination of camera configurations provides overlapping coverage and enhances the installation’s multirole functionality. Pole-mounted fixed cameras using optimized thermal analytics provide automated alarming of intruders while cueing pan and tilt cameras to interrogate alarms for a more detailed threat assessment. When no intrusion alarms are present, the pan and tilt cameras can examine substation components for heat signatures that signify efficiency loss or impending failure and generate temperature alarms.

Thermal cameras that are precisely calibrated do more than just detect differences in heat: they can accurately measure temperatures of distant objects, measure and track those changes over time, and be set to create alarms when temperatures meet or exceed predetermined thresholds.

Substation alarms can be triggered by temperature rises at any electrical connection, insulator, cooling regulator, switch, or anything else. Temperature increases can be caused by mechanical damage, corrosion or myriad other factors. Most utility companies have strict predictive maintenance programs in place, in which operations staff use handheld thermal cameras to methodically inspect each individual component for temperature-related problems.

Being able to do these inspections remotely from a central control station—or even just getting a little advanced warning of a problem so that they can do more targeted in-person inspections—can save utility companies money in inspection costs alone. On top of that, the unscheduled failure of any of the thousands of components in an average substation can potentially cost the utility millions of dollars in revenue. Proactively fixing these faults saves utilities from losing millions of dollars in revenue due to unplanned service interruptions every year.

Bulk Materials and Critical Vessel Monitoring

Bulk materials monitoring can include anything from indoor warehouses to large outdoor coal piles or hazardous chemical storage. High-pressure vessels can be anything from a torpedo car on a rail line to a catalytic cracker or other pressure chamber in a processing plant. What these disparate items have in common is that they need to be guarded from intruders and they need to be monitored to protect the surrounding people and structures.

The same perimeter security requirements apply to a bulk materials security application as they do to security at a substation. The difference comes when monitoring the things inside the wire. Temperature-calibrated thermal cameras can detect areas of incipient spontaneous combustion in coal piles, areas of raised temperature—which can indicate possible leaks or fires—in chemical storage facilities, and localized areas of increased pressure—which cause increases in heat—in pressure vessels.

Similar to the use case for substation security, cameras used in bulk materials and critical vessel monitoring can be pre-configured to send alarms based on usercustomized temperature profiles and limits within the entire surveillance area or within specific alert zones.

Thermal cameras have proven beneficial in both security and condition monitoring/predictive maintenance. Recent technological advancements have allowed manufacturers to combine the functions into a single camera platform.

This article originally appeared in the Security Products Magazine - July 2012 issue of Security Today.

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