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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.

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 giveactual 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 furnishingtemperature 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 athe temperature of a broad range of objects and predict a failure or prevent an unsaoccurrence. 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 alsowhere it is difficult or impossible to add wires associated with traditional temperature sensors. Electrical substations are a primeThere 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 giveactual 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, passivetemperature 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 alsowhere 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.

Applications

• Industry - Mining, Oil & Gas (O&G), Water & Waste o Detect and pinpoint gas leakso Predictive maintenance on o Keeping people out of dangerous areaso Oil Well monitoringo Fire prevention

• Security and

o Automated perimeter securityo Ability to define keep out zones to prevent false alarmso 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 breakdownso Low cooling oil conditionso Connection and splice failures

• Heat loss on

o Heat losso Moisture ingress

• Pollution detection with the

o Automated gas flare detectiono 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 monitoringo Traffic and pedestrian countingo 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 tankSpill 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 enoughPrevent 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