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
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.
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
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
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
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
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
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.