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Thermal & Thermography Cameras with Gas
Detection White Paper
Date: 2nd April 2015
Issue: 8
Company: Pelco by Schneider
Authors: Julian Moss, David Dorn & Alan Wang
Discussion Points
• Thermal Summary
• What is a Thermal Camera?
• What is Thermography?
• Analytics
• DLC (Diamond Like Coating) & Rugged Construction
• Applications
• Radar Integration
• Gas Detection with Thermography & Thermal

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Thermal Summary
Thermal Imaging as with many technologies was developed for the military prior to it
becoming a commercially available product. Older thermal image sensors required active
cooling which made the cameras expensive and required periodic maintenance of the
cameras’ coolers. The production cost with these older sensors and cameras was also quite
expensive. The newer sensors are able to use low cost, commercially available MEMs
(micro-electronic machined) fabrication technologies. The underlying fabrication process
used for game controllers, air bag deployment sensors, and digital projectors is now applied
to infrared image sensors. As thermal technology advances, the price point is significantly
lower making thermal products commercially viable for a many new applications.
Today, cooled thermal sensors still offer higher sensitivity and provide more detail but at a
higher price point. Uncooled sensors offer an instant image display, small form factor, low
power dissipation, and a long mean time before failure. These uncooled cameras are now
easier to install and to maintain further lowering the cost over the lifetime of the application.

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What is Thermal Camera?
Thermal cameras as with conventional cameras require a sensor that can detect a specific
light source to produce an image. We see light/colours described as ‘visible light’ within the
light spectrum.
Look up to the sky after the rain stops and you may see a rainbow as the sun is shining.
Each colour being viewed is a specific frequency of light. These frequencies make up the
colours of the rainbow and what is described as visible light:
Colour wavelength
Red 630-700 nm
Orange 590-630 nm
Yellow 560-590 nm
Green 590-560 nm
Blue 450-490 nm
Indigo 420-440 nm
Violet 400-450 nm
Note: 800nm (nanometers) = 0.8 µm (micrometers)
Thermal cameras detect long wavelength infrared (LWIR) via image sensors with an array of
pixels that detect light within the 7.5-12 µm (micrometers) wavelength range. Infrared energy
hits the sensor with varying heat and corresponding temperature differences across each
pixel on the surface of the thermal image sensor. The difference in temperature of each
pixel is then translated into an electrical signal. The electrical signal from each pixel is
readout and forms what we see as images or a thermogram. A difference in temperature is
translated to a difference in brightness in the thermogram.
Infrared is heat energy with longer wavelengths than visible light. As an object is heated, it
emits exponentially more heat energy. Also as an object is heated, the wavelength
associated with the peak of the emission shifts to shorter wavelengths. This is why when
looking at coals on a fire, for example, that you see the red glow. The object is hot enough
that a portion of the heat energy emitted is now visible to the naked eye. As objects are
heated above room temperature, the heat energy from the object increases exponentially
and the wavelength associated with the peak emission slowly moves to shorter wavelengths.
What is interesting is that all objects omit infrared energy, and this is what a thermal sensor
detects.
Objects around room temperature have a peak heat energy emission around 10µm
wavelength. The un-cooled image sensors in thermal cameras are designed to take
advantage of this fact and optimize their sensitivity around this wavelength. Like visible
wavelengths that the eye can see, the atmosphere also provides very good transmission of
heat energy around 10µm wavelength. This allows a thermal camera to see the heat energy
from objects at a long distance. This fact makes thermal cameras very good at long range
detection of people and vehicles.
Multiple objects within a scene will provide different amounts of heat energy due to their
temperature differences and due to their emissivity differences. Emissivity is a material
property indicating how efficient a material is radiating or outputting its heat energy. The
emissivity differences and temperatures differences create unique fingerprints of each object
in the field of view or scene. This scene is what our video image becomes.

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A visible camera uses plastic or glass that is transmissive from 400nm to 900nm
wavelengths. Thermal cameras must also use lens materials which are transmissive in its
wavelengths of interest (7.5 to 12 µm). Thermal cameras use lens elements made out of
materials such as Germanium, Silicon, and Zinc Selenide. Polypropelyne plastic is also
transmissive to infrared wavelengths. Many of the materials used for thermal infrared lenses
are opaque to visible light. A thermal lens tend to have lower F#s (faster lenses) than
corresponding visible lenses with numbers just slightly higher than F#1 to maintain adequate
heat energy sensitivity. The lens focal length determines the field of view for the camera.
The higher the focal length, then the smaller the angular field of view.

5. What is Thermography?
Within thermal cameras, there is an additional classification for thermography cameras.
Typical thermal cameras show heat signature differences within a scene, but do not give
actual temperature of objects in the scene. Thermography cameras provide this capability.
Thermography cameras must be designed and calibrated to
the heat signature (called radiance) from each pixel.
(visual representation) is a technology furnishing
temperature measurement of an object(s) within a scene of the camera’s field of view.
is an extension of the thermal camera
readings with fast response times offering
Thermography cameras provide a
the temperature of a broad range of objects and predict a failure or prevent an unsa
occurrence. Thermography cameras are most useful where it is necessary to measure a
large number of objects or points in a scene and where it is useful to understand the
temperature gradients and contours with a scene. Thermography is also useful also
where it is difficult or impossible to add wires associated with traditional temperature
sensors.
Electrical substations are a prime
There are many points needing to be measured, for example:
1.
2.
3.
4.
5.
6.
7.
8.
9.
Electrical substations also present a challenge in wiring traditional temperature
to the hazards associated with mixing low voltage and high voltage wiring.
Within thermal cameras, there is an additional classification for thermography cameras.
Typical thermal cameras show heat signature differences within a scene, but do not give
actual temperature of objects in the scene. Thermography cameras provide this capability.
Thermography cameras must be designed and calibrated to be able to precisely measure
the heat signature (called radiance) from each pixel. Thermography or therm (heat)
is a technology furnishing a unique contactless, passive
temperature measurement of an object(s) within a scene of the camera’s field of view.
camera feature set offering pixel by pixel temperature
with fast response times offering real time imagery.
Thermography cameras provide a cost effective, reliable and accurate solution to monitor
the temperature of a broad range of objects and predict a failure or prevent an unsa
Thermography cameras are most useful where it is necessary to measure a
large number of objects or points in a scene and where it is useful to understand the
temperature gradients and contours with a scene. Thermography is also useful also
where it is difficult or impossible to add wires associated with traditional temperature
Electrical substations are a prime example where thermography is especially applicable.
There are many points needing to be measured, for example:
Power transformers - oil levels and pump operation
Load tap changers - oil levels other internal problems
Insulator bushings - oil levels and bad connections
Standoff insulators - moisture, contamination, degradation
Lightning arrestors - degradation of metal oxide disks
Circuit breakers - oil
Mechanical disconnects - bad connections, contamination
Control cabinets - wear and tear on pumps and other components
Batteries
Electrical substations also present a challenge in wiring traditional temperature sensors due
to the hazards associated with mixing low voltage and high voltage wiring.
Images from the Victoria & Albert in Cape
Town in Colours, White Hot & Black Hot.
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Within thermal cameras, there is an additional classification for thermography cameras.
Typical thermal cameras show heat signature differences within a scene, but do not give the
actual temperature of objects in the scene. Thermography cameras provide this capability.
be able to precisely measure
(heat) graph
, passive
temperature measurement of an object(s) within a scene of the camera’s field of view. This
y pixel temperature
to monitor
the temperature of a broad range of objects and predict a failure or prevent an unsafe
Thermography cameras are most useful where it is necessary to measure a
large number of objects or points in a scene and where it is useful to understand the
temperature gradients and contours with a scene. Thermography is also useful also useful
where it is difficult or impossible to add wires associated with traditional temperature
example where thermography is especially applicable.
moisture, contamination, degradation
bad connections, contamination
wear and tear on pumps and other components
sensors due
Images from the Victoria & Albert in Cape
Town in Colours, White Hot & Black Hot.

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Analytics
Pelco by Schneider has created temperature data that can be utilised on-board the
thermography camera in the form of analytics. When enabled camera-side, specific key rules
can be applied to the subject process and/or equipment in the cameras field of view. Having
the ability to run multiple rules over multiple regions of interest maximises the return on
investment, if there is a requirement to report multiple instances of temperature readings
concurrently.
An advantage to the data is the ability to trigger temperature alarms from the camera and/or
have external centralised application(s) manipulate the data for its’ desired task. Video
Management System (VMS), SCADA (Supervisory Control and Data Acquisition) an
industrial process and control system or computer applications can run their own routines as
well as receive alarm data and thermal images from the camera.
For example, the thermography camera continuously feeds contactless temperature data
and alarms if required centrally. Should excessive heat on a conveyer belt or motor at a
mine be detected; the centralized software has the capability of stopping the process
preventing a break down by receiving the temperature data and/or alarm reporting a
maintenance requirement or preventing a fire.
Thermal camera temperature measurement technology offers the following detection or
alarm notification thresholds via analytics absolute, relative and self reference.
Absolute Threshold
Detects temperature changes to objects or areas within a defined zone. An alarm
triggers when the threshold temperature range is exceeded (high and/or low).
Relative Threshold
Detects temperature differences between objects in a group (a group being two or more
objects). An alarm triggers when the threshold temperature range is exceeded.
Self Reference
Detects changes in the current temperature from the initial temperature defined in the
self-reference zone when the box is drawn. An alarm triggers when the temperature
change has exceeded the threshold.

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Pelco DLC (Diamond Like Coating) Protection on the Germanium Window.
We use a diamond-like carbon coating (DLC) on all of our windows and lenses to
provide protection of the outer optical surfaces from the environment (humidity, dust,
atmospheric precipitations). DLC stays inert to mechanical strikes, thermal shock,
acids, salts, solvents, and other chemical reagents.
The DLC coating is specified to meet the following test conditions (known as
the ‘5000 revolutions wiper sand test’ - This coating will show no signs of removal
when exposed to 5000 revolutions of a wiper blade under 40 grams load using a
sand and water mixture consisting of 1cc of sand to DEF STAN 07-55 Type C, in
10ml of water or equivalent. The coating will show no evidence of deterioration
when subjected to the salt spray fog test per
MIL-C-675, severe abrasion and adhesion test per
MIL-C-48497, and the windscreen wiper test in the sequence listed. Following
this test, the coating shall be exposed to a relative humidity between 95 and
100 percent at a temperature of 120 degrees F ± 4 degrees F for a period of
672 hours. After this test, the coating shall again be subjected to the severe
abrasion and adhesion test of MIL-C-48497 in the sequence listed here and
shall conform to the requirements of paragraphs: Physical, Environmental and
Solubility, Blemishes, Spatter and Holes, and Surface Defects. Other relevant
specifications:
The coating is unaffected by immersion in:
* Dilute HCL for 10 minutes
* Salt solution for seven days
* Water for 28 days.
Ruggedized
All the thermal TI products are IP66 and NEMA type 4 for use with applications both
indoor/outdoor.
For Harsh environments, Sarix Thermal Fixed and the Esprit® pan & tilt series have
an optional marine finish through applying a ‘hard clear anodized coat’ to the
casework prior to the final powder coat process. This finish is also flame resistant
making the TI range perfect for mining, marine and industrial applications.

8. Applications
• Industry - Mining, Oil & Gas (O&G), Water & Waste
o Detect and pinpoint gas leaks
o Predictive maintenance on
o Keeping people out of dangerous areas
o Oil Well monitoring
o Fire prevention
• Security and
o Automated perimeter security
o Ability to define keep out zones to prevent false alarms
o Ability to recognize and identify in addition to
• Life safety and fire prevention.
o Alarm based on materials or machinery nearing flashpoint
temperatures
• Excess load dete
o Detect insulator breakdowns
o Low cooling oil conditions
o Connection and splice failures
• Heat loss on
o Heat loss
o Moisture ingress
• Pollution detection with the
o Automated gas flare detection
o Gas leak detection
• Water & Oil Tank
o Ability to remotely measure water levels outside of the
o Spill and leak detection
• Plant maintenance
• Automotive,
o Brake temperature monitoring
o Traffic and pedestrian counting
o Platform side monitoring for rail
• Frozen food
o Food safety monitoring
o Prevent food spoilage in food distribution warehouses
• Temporarily d
required
o Construction site monitoring and
o Concert and sporting events
• In addition process control, h
Mining, Oil & Gas (O&G), Water & Waste Water (WWW)
Detect and pinpoint gas leaks
Predictive maintenance on machinery
Keeping people out of dangerous areas
Oil Well monitoring
Fire prevention
Security and perimeter detection
Automated perimeter security
Ability to define keep out zones to prevent false alarms
Ability to recognize and identify in addition to detection
Life safety and fire prevention.
Alarm based on materials or machinery nearing flashpoint
temperatures
Excess load detection within the power industry
Detect insulator breakdowns
Low cooling oil conditions
Connection and splice failures
Heat loss on building structures
Heat loss
Moisture ingress
Pollution detection with the environmental agencies
Automated gas flare detection
Gas leak detection
& Oil Tank Level monitoring
Ability to remotely measure water levels outside of the tank
Spill and leak detection
lant maintenance and preventative maintenance/monitoring
utomotive, Rail & Aviation
Brake temperature monitoring
Traffic and pedestrian counting
Platform side monitoring for rail
Frozen food storage and low temperature processes.
Food safety monitoring – temperature not hot or cold enough
Prevent food spoilage in food distribution warehouses
Temporarily deployable low power usage where zero light monitoring is
Construction site monitoring and perimeter security
Concert and sporting events
process control, heat Management, and general R&D
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(WWW)
Alarm based on materials or machinery nearing flashpoint
tank
and preventative maintenance/monitoring
temperature not hot or cold enough
ro light monitoring is
eneral R&D

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Radar Integration
The X300 a deployable self sufficient Mobile Sensor Station is supplied by
Reutech South Africa.
X300 was utilised to demonstrate the integration capabilities of the SpotterRF
Radar detection system when integrated with the Pelco Thermal Imaging
Positioning System, powered by a managed solar solution.
A combined radar detection system backed-up with thermal video visual
verification acts as a proficient solution where PIMS (Perimeter Intrusion
Monitoring Systems) utilise the SpotterRF Radar and Pelco Thermal Esprit Positioning System and
Pelco Esprit 2 Megapixel Day/Night Positioning systems. SpotterRF has the capability to drive 2x
Pelco Positioning System cameras, providing a cross sectional view to operator from two different
angles - essential for perimeter monitoring.
Traditionally used for asset protection with surveillance radar technology. The
PIMS radar technology provides all-weather, persistent wide area surveillance.
These technologies enable superior intruder detection and tracking capability
both during the day and at night in the harshest of environments.
The integration works through Geo-referenced 2D intruder tracking by the
SpotterRF radar sub-system providing automatic cueing (movement) of the
integrated P&T (Pan & Tilt) Thermal or PTZ (Pan Tilt & Zoom) Day Night
cameras.

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Gas Detection
Gas detection due to leakage is a growing requirement for health and safety
reasons, environmental concerns and regulations, and also loss of revenues
to manufacturers due reductions in yield.
How can thermal cameras provide a solution?
If we consider that the infrared wavelength ranges from 7.5-12 µm (Long Wavelength
Infrared Range), many gases of interest have strong absorption lines in this region. These
absorption lines mean that less thermal or heat energy comes from areas in the scene
where these gases are present. In a thermal image, gas leaks show up as dark regions in
the image. This provides the means to potentially detect the following gasses to name a few:
Gases Detection Using LWIR
(Long Wavelength Infrared) Cameras (8-12µm)
SF6 Sulphur Hexafluoride Acetyl Chloride Methyl Vinyl Ketone
NH3 Anhydrous Ammonia Allyl Bromide Propenal
ECA Ethyl Cyanoacrylate
(‘Superglue’)
Allyl Chloride Propane
CIO2 Chlorine Dioxide Allyl Fluoride Tetrahydrofuran
CH3 Acetic Acid Bromomethane Trichloroethylene
R-12 or CFC-12 FREON-12 FREON-11 Uranyl Fluoride
C 2H 4 or H₂ Ethylene Fura Vinyl Chloride
MEK Methyl Ethyl Ketone Hydrazine Vinyl Cyanide
Methylsilane Vinyl Ether
The gases listed above provide a high level of contrast in the scene lending itself to
automated analytics for gas leak detection. Using thermal imaging technology provides
distinct advantages to other point sensing technologies. Unlike point sensors, the ability to
image the gas provides the ability to quickly pinpoint the source of leaks and to quickly
estimate gas volume associated with leaks.

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It is difficult to differentiate between gas types using thermal
technology, but when used in the correct environment acts as a
powerful tool.
Thermography with gas detection opens up a new chapter
regarding preventative care/maintenance or life safety. Consider a
valve is leaking explosive gas in a high temperature environment.
We now have the ability to watch from a safe distance the
temperature level and gas flow with visual imagery in real time
allowing an operator to take corrective action at a critical site.
Products supporting hardware gas detection backed up with a unique algorithm that look at
the gas flow provides a far more reliable gas detection system for process monitoring or gas
leak , products supporting both hardware and software detection