2011
January 04, 2011
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Frostbite & Hypothermia
“Jack Frost nipping at your nose.” These lyrics from a popular Christmas carol evoke romantic visions of winter; however, frostbite and hypothermia are dangerous medical conditions that can present serious safety hazards.
For many, the dead of winter is upon us. Thermographers working outdoors in cold climates can face serious safety challenges due to frostbite and hypothermia. Knowing the symptoms of these conditions and proper treatment is imperative for worker safety.
Frostbite is a severe reaction to cold exposure that can permanently damage its victims. A loss of feeling and a white or pale appearance in fingers, toes, or nose and ear lobes are symptoms of frostbite.
Hypothermia is a condition brought on when the body temperature drops to less than 90 degrees Fahrenheit. Symptoms of hypothermia include uncontrollable shivering, slow speech, memory lapses, frequent stumbling, drowsiness, and exhaustion.
If frostbite or hypothermia is suspected, begin warming the person slowly and seek immediate medical assistance. Warm the person’s trunk first. Use your own body heat to help. Arms and legs should be warmed last because stimulation of the limbs can drive cold blood toward the heart and lead to heart failure. If the person is wet, put them in dry clothing and wrap their entire body in a blanket.
Never give a frostbite or hypothermia victim beverages containing caffeine or alcohol. Caffeine, a stimulant, can cause the heart to beat faster and hasten the effects the cold has on the body. Alcohol, a depressant, can slow the heart and also hasten the ill effects of cold body temperatures.
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January 10, 2011
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NOTICE OF COPYRIGHT
Tip provided by:
Robert J. Incollingo
416 Black Horse Pike
Glendora, NJ 08029
856-234-3800
www.rjilaw.com
The prescribed form of copyright notice for infrared images and other “visually perceptible copies” should contain all the following three elements:
(1) The symbol © (the letter C in a circle), or the word “Copyright,” or the abbreviation “Copr.”; and
(2) The year of first publication of the work; and
(3) The name of the owner of copyright in the work, or an abbreviation by which the name can be recognized, or a generally known alternative designation of the owner.
Example: © 2011 Infraspection Institute
While the use of a copyright notice is no longer required under U. S. law, it still has importance because it informs the public that your work is protected by copyright, identifies you as the copyright owner, and shows the year of first publication of the copyrighted work. Copyrights generally last for the life of the author plus 70 years, so logically, the year of publication is unimportant in figuring when the copyright expires, but can be relevant in any court battle over alleged infringement. Given these benefits, when you feel your creation deserves protection, you should use a copyright notice and use it correctly.
Bob Incollingo is an attorney in private practice in New Jersey and a regular speaker at Infraspection Institute’s annual IR/INFO Conference.
January 17, 2011
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IR Inspections of Insulated Windows
Tip written by: Infraspection Institute
Infrared inspections of building envelopes can provide evidence of excess energy loss through walls, doors and roofs. Under the right conditions, thermal imagery can also provide evidence of excess energy loss through insulated window assemblies.
Insulated windows are a common feature found on modern commercial and residential structures. Unlike single pane windows, insulated windows are manufactured with an Insulating Glass Unit (IGU). An IGU typically consists of two or more layers (lites) of glazing separated by a spacer along the edge and sealed to create a hermetically sealed air space between the layers. IGUs are then encased within a sash or fixed frame in order to facilitate installation.
In order to increase the insulating performance of an IGU, the air space between the lites may be filled with air or inert gases like argon or krypton. Typically the spacer is filled with desiccant to prevent condensation. For some IGUs, most of the air is removed to further reduce convection and conduction through the finished IGU.
Over time, IGUs seals can fail causing inert gas to be lost and/or allowing humid air to enter the assembly. Unless condensation occurs between the lites, failed IGUs are difficult to detect; however, they may be readily detected using a thermal imager under the proper conditions.
center of insulated window. Pattern typical of failed IGU seal.
Infrared inspection of insulated windows and building envelopes is one of many topics to be covered during Infraspection Institute’s annual technical conference, IR/INFO 2007 being held January 14 – 17, 2007 in Orlando, FL. For more information or to register, visit us online at www.infraspection.com or call us at 609-239-4788.
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January 24, 2011
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The One Hundred Dollar Nail
Tip and images provided by Stuart L. Raney Infraspection Institute Level III Certified Infrared Thermographer
“How much is that infrared inspection worth anyway?”
I don’t remember for sure if it was my dad or maybe my uncle who first pointed out a $100 nail. I can say it was some time ago because that $100 nail would be worth several hundred now. I also don’t remember where I was the first time I found a $100 nail or how many more I have found thru the years. Every now and then you might find one worth thousands and one could argue that some of them may be priceless.
We were likely somewhere on the farm, probably near one of the barns when they asked me would I mind picking up that 100 dollar bill by my left foot. I looked down and didn’t see any sign of a 100 dollar bill, but there lay this old rusty nail so I reached down, picked it up and at the same time asked where the money was.
Then it was explained to me that had the old rusty nail not been picked up, it very well could have ended up in a tractor tire, might ruin the tire which could cost $100 or more to replace. Since a penny saved is a penny earned, the nail in hand was easily worth a hundred dollars. Today that $100 nail would be worth several hundred. A nail found that prevents a blowout out on the highway could be worth thousands and a nail found, for instance, in a school bus yard could be priceless.
Infrared inspections of low slope insulated roof systems, and many other applications, are a lot like looking for $100 nails. You have to gauge your success and the worth of the inspection by what you have prevented and not so much by what you have found. A roof inspection that finds five small wet areas on a 2 year old 100,000 square foot roof may have saved replacing that roof several years before it was planned making that $5,000 inspection worth several hundred thousand dollars.
Infrared inspections provide value by preventing unplanned repairs and replacements. The best value and the most savings is realized when the inspection finds the minor problems that are easy and inexpensive to repair.
Just like picking up old rusty nails.
Stuart Raney is President of Infrared Building Diagnostics, LC, an infrared consulting firm headquartered in Winchester, KY
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January 31, 2011
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Why Imagers & Radiometers Disagree
As the awareness of non-contact temperature measurement has increased, spot radiometers have become common tools in the workplace. Discrepancies frequently arise when temperatures taken with spot radiometers are compared to temperatures obtained with an imaging radiometer.
Advances in technology and increased sales volume have allowed several manufacturers of spot radiometers to offer a number of models priced below $100. Lower cost, combined with a greater awareness of infrared thermometry, has allowed most maintenance personnel to incorporate spot radiometers into their toolboxes.
When a thermographer reports temperatures obtained with an imaging radiometer, maintenance personnel will frequently attempt to cross-verify reported temperatures with a spot radiometer. In such situations, discrepancies are common as the spot sizes of imaging radiometers and spot radiometers often vary widely. In order to ensure measurement accuracy and avoid discrepancies, one should bear the following in mind:
- For accurate temperature measurement, radiometers must be operated correctly and in accordance with manufacturer’s instructions
- Radiometer accuracy can degrade over time or with physical stress
- Spot radiometers will generally have spot measurement sizes that are larger than imaging radiometers
- When spot measurement sizes vary between instruments, reliable cross-verification is not possible
To avoid discrepancies, personnel who utilize infrared radiometers should be trained in the proper use of their test equipment along with its limitations. Personnel must also understand how the characteristics of infrared instruments affect the accuracy of observed temperatures. Lastly, using cross-verification of temperatures should be avoided when radiometer capabilities differ from each other.
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February 07, 2011
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Winter Driving Tips
Tip written by: Infraspection Institute
With an unusually harsh winter well underway, many have already experienced driving challenges associated with severe weather. With this Tip, we offer some advice for driving in winter conditions.
Prepare Your Vehicle
- Make sure brakes, windshield wipers, defroster, heater and exhaust system are in top condition
- Check radiator for coolant level and adequate antifreeze protection. Fill windshield washer reservoir with freeze-resistant fluid
- Check tires for proper inflation and tread condition
- Carry an ice scraper, brush, and a shovel
- Maintain a full gas tank in case of traffic delays or should you need to turn back due to conditions
- Keep snow chains handy and in good condition
Driving Tips
Lastly, be certain to wear your seat belt. Consult your local weather forecast before you set out and consider postponing your trip if extreme weather is predicted.
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February 14, 2011
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Training and Equipment: Which First?
We’ve all heard the phrase, “Put the horse before the cart.” When it comes to thermography, many people put the cart in front of the proverbial horse by buying infrared equipment before obtaining proper training.
Purchasing the correct imager is a challenge for many reasons: initial purchase price can be costly, no imager is capable of performing all applications, imager performance varies widely, and available specifications are frequently exaggerated.
Further compounding this challenge is that many manufacturers offer “free training courses” as sales incentives to purchasers of new equipment. Frequently these free courses are taught by inexperienced/unqualified instructors, are introductory in nature, and are designed as operator courses for the subject equipment omitting important theory or applications. Because these courses are taught after equipment is delivered, inexperienced purchasers lack the knowledge required to make an informed decision when selecting new equipment.
In order to properly select and specify infrared equipment, buyers should put the horse before the cart by receiving quality certification training from an independent institute prior to equipment purchase. For new users, training should include infrared theory and heat transfer concepts, equipment selection and operation, image capture and analysis, standards compliance, applications-specific inspection techniques, documentation of findings, and temperature measurement techniques.
Infraspection Institute offers Level I, II, and III training and certification for thermographers worldwide. Our cutting-edge infrared training courses are taught by highly-experienced thermographers in a friendly, relaxed atmosphere without marketing hype. For more information call 609-239-4788 or visit us at www.infraspection.com.
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February 21, 2011
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Infrared Inspection of Capacitors
Capacitors are devices commonly found in AC electrical distribution systems where power factor correction is required. Like any electrical component, capacitors need to be regularly checked for proper operation. Infrared thermography can be used to rapidly inspect capacitors from a safe, remote distance.
Capacitors are wound devices that are electrically connected between potential and ground. Capacitors used for power factor correction are generally encased in painted, rectangular steel canisters and often have two equal sized bushings for electrical connections. In a three phase circuit, there may be several capacitors connected to each phase.
The most common failures of capacitors are loose/deteriorated bushing connections, open circuits due to internal winding failure, and open supply circuits. When inspecting capacitors, be sure to:
- Visually inspect capacitor bodies. Capacitors should not be misshapen/ swollen.
- Thermographically inspect capacitor bodies. Energized capacitors should be warmer than ambient air temperature and exhibit equal temperatures across all phases.
- Check bushing and wiring connections for hotspots.
Any thermal anomalies detected should be investigated and corrected as soon as possible. Capacitors operating at ambient temperature should be corrected immediately as imbalanced capacitance can be more detrimental than having no capacitors at all.
Infrared inspection of power distribution systems is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems & Rotating Equipment, visit us online at www.infraspection.com or call us at 609-239-4788.
February 28, 2011
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How Close Do You Need to Be
One of the most frequently asked questions in thermography is, “How close do I need to be to my target?” The answer depends upon target size and the type of data that are desired.
Appropriate distance is largely dependent upon three factors: target size, IR equipment optics, and detector resolution.
With qualitative thermal imaging, the maximum viewing distance is achieved where the object and any possible anomalies can be clearly resolved. If a target cannot be clearly distinguished, it will be necessary to move closer or to use a telephoto optic.
When using an imaging radiometer, obtaining accurate temperatures will require substantially shorter distances than those required for thermal imaging. Obtaining accurate quantitative data requires that the radiometer’s spot measurement size is smaller than the area being measured. If it is determined that the radiometer’s spot size is larger than the area being measured, it will be necessary to move closer or use a telephoto optic calibrated for the imager.
Because there is no method for correcting for errors caused by imaging at excessive distances from a target, it is imperative to always ensure appropriate distance prior to recording images.
Spot measurement size and its impact on accurate temperature measurement is one of the many topics covered in the Level II Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training or to obtain a copy of the Standard for Measuring Distance/Target Size Values for Infrared Imaging Radiometers, visit us online at www.infraspection.com or call us at 609-239-4788.
Why GFCI Devices Appear Warm
When performing an infrared inspection of an electrical panel you may notice that the phenolic bodies of Ground Fault Circuit Interrupters appear warm. This same condition may also be observed on self-contained GFCI receptacles. This condition is usually due to the construction of the device itself.
In order to monitor the amount of current flowing through the supply and neutral conductors of a circuit, GFCI devices have small transformers built into them. These transformers can cause the body of the GFCI to run several degrees warmer than ambient temperature. Depending upon the settings of your thermal imager, these device may show a marked contrast to their surroundings.
When inspecting GFCI devices, compare the thermal patterns of these devices to other similar devices under similar load. When inspecting GFCI breakers, be sure to inspect the load side connection at the GFCI device as well as the neutral bus bar connection for the subject breaker.
Infrared inspection of electrical distribution systems is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems & Rotating Equipment, visit us online at www.infraspection.com or call us at 609-239-4788.
Emissivity Settings for Building Inspections
Tip written by: Infraspection Institute
A common question among thermographers who perform infrared inspections of buildings is, “What emissivity setting should I use?” While this might seem like a straightforward question, the answer is not that simple.
Recent years have seen a dramatic increase in the use of thermography as a building diagnostics tool. While many applications are qualitative, there are occasions when quantifying temperature can be useful. In order to accurately perform non-contact temperature measurements, one must input the correct emittance value into a radiometer’s computer.
While many equate emissivity to values published in emittance tables, emissivity is a dynamic characteristic that is influenced by several factors. These include: wavelength, object temperature, viewing angle, target shape, and surface condition. Each of these factors can vary between projects or during a given inspection.
Further compounding the challenge is the fact that not all imagers are created equal. Imagers lacking corrective inputs for atmospheric attenuation and/or reflected temperature often require an exaggerated emittance value be utilized.
When performing an infrared inspection of buildings, keep the following in mind:
- For qualitative inspections performed with an imaging radiometer, leave the imager’s E control set to 1.0. If possible, turn off all temperature measurement tools.
- In general, dielectric materials will have a relatively high emittance; shiny surfaces and glass will be quite reflective.
- Viewing angle and reflected temperature can greatly influence the effective emittance of a material. In particular, smooth-surface roof membranes and building sidewalls can be quite reflective when imaged at low viewing angles often associated with ground-based inspections.
Lastly, emittance values obtained from published tables can introduce significant temperature measurement errors. Whenever possible, one should calculate emittance values with the subject imager and cross verify observed temperatures with contact thermometry.
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Focus, Focus, Focus
Tip written by: Infraspection Institute
Proper image focus is still one of the most important aspects of performing an infrared inspection. A clear image not only allows for optimal problem diagnosis, but it is also critical to accurate temperature measurement.
Clear focus is not difficult to achieve if you follow a few simple steps:
- Get as close as safely possible to your target
- Take time to carefully focus for optimum clarity. This may take some practice if you have a motorized focus mechanism.
- Ascertain that your target is stationary.
- Only shoot from a stable platform. If imaging from a motor vehicle, it may be desirable to shut off the engine to avoid vibration.
- Be sure your imager is steady as you capture the image. Gently push the store button rather than punching it.
- If using a handheld imager, consider using a tripod or monopod to help stabilize your imager.
Once you’ve stored an image, recall and check for clarity. If the results are less than perfect, start over. In addition to greater accuracy, capturing clear images makes it easier to convey information to the end user and/or the person who will eventually perform corrective actions.
Infrared imager operation is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information or to register for a course visit us online at www.infraspection.com or call us at 609-239-4788.
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Combining IR Imaging and Ultrasound
to Find Pipe Leak
Tip provided by
Richard W. Rhoades
Level II Infraspection Institute
Certified Infrared Thermographer®
Locating pipe leaks hidden within finished walls can be tricky. In this Tip we examine the use of thermal imaging and airborne ultrasound to help pinpoint the source of a leak.
Ever had one of those pesky water plumbing leaks in your house, but loathed the idea of tearing out ever-larger sections of ceiling, walls, and floors to find the source? An IR inspection can often ‘see’ thermal profiles created by wet building materials, but an airborne ultrasonic detector can be useful to ‘hear’ and help pinpoint the leak source.
Recently, we found water soaked ceilings and walls in our mid-level bathroom and adjoining laundry room, and water dripping into the basement below. We suspected a leak in the household plumbing system. Most dripping ceased within a few hours of shutting off the city water supply.
So where does one start with tearing out ceilings, walls, and floors to find a water leak?
As an alternative to gross demolition, I drained the household water system, and pressurized it with a small air compressor to about 50 psi. With a UE Systems Ultraprobe 9000 in ‘airborne’ mode, I started scanning and ‘listening’ for air leakage signals from the wet ceilings and walls in the laundry room and bathroom. Within a minute, a faint (very high frequency) leaking indication was detected from a ceiling area directly above the bathroom sink.
I cut out a 10” area of sheetrock to allow better access to the noise source and found the noise emanating from a soldered joint of half-inch copper tubing. Even with this leak exposed, the ‘noise’ could not be detected by the unaided human ear. Yet the Ultraprobe had originally ‘heard’ the leak noise even with the sheetrock in place.
In this case the leak source was quickly located, potentially saving thousands in home repair bills. As is the case with thermal imaging, training and experience are essential to become proficient in the effective use of ultrasonic sound detectors.
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Infrared Inspections of UPS Systems
Tip written by: Infraspection Institute
Uninterruptible Power Supply (UPS) systems are commonly found in facilities where reliable electrical power is critical. Infrared inspections can play a key role in maintaining these crucial systems.
An Uninterruptible Power Supply (UPS) system is an electrical apparatus that provides short-term emergency power to a load when the normal input power source fails. Unlike standby generators, UPS systems provide instantaneous protection from input power interruptions by means of attached batteries.
UPS systems are typically used to protect computers, data centers, telecommunication equipment or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious business disruption, or data loss. Due to their critical role, it is imperative that UPS systems be maintained to ensure reliability when needed.
Performed under the correct conditions, thermal imaging can be useful in detecting defects within a UPS system including loose or deteriorated connections, overloads, and faulty components. When combined with regular preventive maintenance, thermal imaging can detect faults that are undetectable by other means.
When performing an infrared inspection of a UPS system, keep the following in mind:
- Panel covers should be opened or removed to afford line-of-sight access
- UPS system must be under load
- Be certain to include all current carrying devices including UPS system controls, switchgear, battery cells, battery bus, and wiring
- Inspect battery casings for discrete hot spots
- Compare batteries to each other noting any with elevated temperatures
Thermal imaging may be applied during normal operation of the UPS system or during a controlled discharge test. If imaging during the latter, a thermographer will have to work quickly to ensure complete coverage of the subject components.
Lastly, be certain to observe all necessary safety practices when working on or near energized electrical equipment.
Infrared inspection of power distribution systems is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems & Rotating Equipment, visit the Infraspection website or call us at 609-239-4788.
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Care and Feeding of Infrared Lenses and Other Optics
Tip provided by
Wayne Swirnow – Infrared Imaging Services LLC
Like all fine optics, the lens of an infrared camera must be treated with special care to maintain the integrity of the image and accuracy of the information you are expecting it capture.
As with most lenses, an infrared camera lens has a spectrally selective coating on its front surface that is specifically designed to be the transmissive in the frequencies of infrared energy.
Damage to the coating on the lens surface can change the bandpass and rejection of the selective coating modifying the amount of infrared energy transmitted through the lens and onto the detector chip, thereby changing the amount of infrared energy the camera sees and therefore the cameras calibration.
In fact, a large degradation in a specific area such as a deep scratch on the surface of the lens could require a re-recalibration of the camera because the pixels behind that area will receive a different amount of infrared energy than the other pixels on the chip where the lens is not damaged will.
To properly clean an optical surface, first all dust and grit or other abrasive material must be removed. This is done usually with some type of air blower or puffer and a specially designed very soft brush. If using a can of compressed air be sure to not allow the cold liquid to strike the surface of the lens. Never wipe any lens with a cloth or lens tissue without first removing any dust and grit from the lens with an air stream and fine brush. Wiping a lens before removing any dust and dirt that is like using sandpaper on the fine and fragile optical coating.
Once the lens surface has been cleaned of any grit, is then permissible to use a soft cloth to remove smudges or fingerprints. Never use any cleaning liquids on the lens unless it is approved for use by the camera lens manufacturer.
In general, good camera hygiene would be to wipe the entire camera down with a soft cloth removing any exterior dust and dirt after each days use. When charging batteries look at the contacts to ensure they are clean, not bent, and free of any dirt or grease.
Occasionally it may be necessary to use a vacuum cleaner on the camera’s carrying case to remove dirt and dust which can accumulate over time in the case. Wipe dust off the battery charger, cables, and any components that go in the case with the camera. Periodic cleaning of your camera and optics can help to ensure proper operation and a long life.
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Using an Isotherm to Detect Potential Condensation Sites
Tip written by: Infraspection Institute
Condensation on interior building surfaces can lead to a variety of problems including conditions conducive to mold growth. Used properly, the isotherm feature found on many infrared imagers can be utilized to spot potential condensation sites.
Simply put, dew point is the temperature at which water vapor in the air will cause condensation to form on a surface. When interior building components are cooled to dew point temperature or lower, water vapor will precipitate out of the air causing water to form on the subject component.
For building envelopes, chronic condensation on interior drywall surfaces can cause unsightly staining by trapping dust or smoke particulates in these areas. Chronic condensation on organic building components is also conducive to mold growth. Condensation often goes unnoticed until building occupants notice stains associated with the aforementioned conditions. Fortunately, a thermal imager can be used to detect condensation problems before they become serious.
To utilize a thermal imager to detect potential condensation sites, identify the dew point temperature for the room or areas that you are inspecting. Set your imager’s isotherm function to appear at, and for several degrees below, the dew point temperature. As you inspect high emittance building surfaces from the interior of the building, note any components that cause the isotherm to appear. These areas should then be further investigated for cause and appropriate action taken.
When using an isotherm, be sure to practice proper measurement techniques giving particular consideration to viewing angle, spot measurement size and emissivity settings.
Infrared inspections of building envelopes is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online or call us at 609-239-4788.
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Ladder Safety – Part 1
Tip written by: Infraspection Institute
For many thermographers, ladders provide a means for accessing remote areas and equipment. Taking the time to use ladders properly can help to prevent serious or fatal injuries.
According to OSHA, falls from portable ladders are one of the leading causes of occupational fatalities and injuries. When using portable ladders, always keep the following points in mind:
- Avoid electrical hazards. Look for overhead power lines before handling a ladder.
- Inspect ladders before each use. Remove broken ladders from service and repair or discard.
- Do not exceed ladder load rating. Be aware of user’s weight including tools.
- Use a ladder only on a stable, level surface. Do not stack ladders on boxes, barrels, or unstable platforms to gain additional height.
- Maintain a 3 point contact with ladder (two feet, one hand). Always face the ladder when climbing and keep your body centered between the rails.
- Ladders should be free of slippery material on rungs, steps or feet.
- Never stand on the top step or rung of a ladder unless it is designed for this purpose.
Lastly, permanent ladders should be checked prior to use to ensure that they are securely attached to their structure.
Thermographer safety is one of the topics covered in all Infraspection Institute Certified Infrared Thermographer® training courses. For information on thermographer training and certification, visit us online at www.infraspection.com or call us at 609-239-4788.
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Ladder Safety – Part 2
Tip written by: Infraspection Institute
For many thermographers, ladders provide a means for accessing remote areas and equipment. In this week’s Tip we cover safety tips applicable to extension ladders.
According to OSHA, falls from ladders are one of the leading causes of occupational fatalities and injuries. When using portable extension ladders, always keep the following in mind:
- Avoid electrical hazards. Look for overhead power lines before handling a ladder.
- Inspect ladders before each use. Remove broken ladders from service and repair or discard.· Use a ladder only on a stable, level surface. Do not stack ladders on boxes, barrels, or unstable platforms to gain additional height.
- Extension or straight ladders used to access an elevated surface must extend at least 3 feet above the point of support. Never stand on rungs above the point of support.
- The proper angle for setting up a ladder is to place its base one quarter of the working length of the ladder from the wall or other vertical surface.
- Be certain that all locks on an extension ladder are properly engaged.
- Do not exceed ladder load rating. Do not move or shift a ladder while a person or equipment is on the ladder.
Lastly, a ladder placed in any location where it could be displaced by other work activities must be secured to prevent displacement or a barricade erected to keep traffic away from the ladder.
Thermographer safety is one of the many topics covered in all Infraspection Institute Certified Infrared Thermographer® training courses. For information on thermographer training and certification, visit us online at www.infraspection.com or call us at 609-239-4788.
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Measuring Motor Temperatures
Tip written by: Infraspection Institute
Temperature can be an indicator of the condition of installed electric motors; however, the best location for measuring temperature is often debated. In this Tip we discuss the best location for measuring motor temperatures.
Measuring motor temperature is often a challenge since electric motors differ widely in their design and construction. While many have suggested measuring the motor casing along the stator, this method does not work well for motors that are fan cooled or exposed to external air currents. For uncooled motors, this approach can produce varying temperature values depending upon the location of the subject temperature readings.
In 1997, a research project led by Infraspection Institute utilized instrumented motors in a controlled environment to determine the effect of excess force on installed motors. One of the primary goals of this research was to identify a location for collecting reliable temperature data.
From our research it was found that measuring the exterior of the motor bellhousing within 1” of the output driveshaft consistently produced temperatures that were within 1 to 2 C of the motor windings and the output side bearing assembly. Temperatures taken at the bellhousing were especially useful for fan cooled motors since this area was unaffected by convective cooling from the fan.
When measuring motor temperatures, keep the following in mind:
- Make certain that all thermometers are within calibration and used properly
- Motor temperature will vary with load and ambient temperature. Be certain to record both with along motor temperature
- Elevated temperatures can be caused by electrical or mechanical defects within the motor and/or defective installations
- Motors with elevated temperature should be further investigated for cause and repaired or replaced accordingly
Temperature limits and trending of two of the many topics covered in the Level II Infraspection Institute Certified Infrared Thermographer® training course. For more information on upcoming classes or to obtain a copy of our Cross Technologies Study, call 609-239-4788 or visit us online at www.infraspection.com.
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Images and Reports – Who Owns Them?
Tip written by: Infraspection Institute
It is said that, “Possession is nine tenths of the law. When it comes to infrared data, ownership is often not that simple. In this Tip we explore the frequently misunderstood topic of infrared data ownership.
Thermograms and hardcopy reports are commonly produced for infrared inspections. Like proud parents sharing photographs of children, thermographers frequently share images, data, and reports with others. During these demonstrations, it is not uncommon to hear thermographers refer to this work product as “my images” and “my reports”. For the purposes of casual conversation, referring to work product in the possessive sense is acceptable; however, the actual owner of such data is often someone else.
Under a principle known as ‘Shop Rule’, data produced by thermographers as part of their duties as an employee belongs to their employer. In general, Shop Rule will always apply unless there is a written agreement to the contrary. For thermographers who work as consultants, a principle known as ‘Works for Hire’ may apply. Under this principle, any work product generated belongs to the client and not the thermographer.
Thermographers who work as consultants should be mindful that contracts and written agreements often have ‘Works for Hire’ clauses. These clauses may appear in the body of a contract or purchase order or be incorporated by reference. Thermographers who wish to retain ownership should address this issue prior to the commencement of any work.
Prior to using infrared data for any purpose other than its original intent, always obtain permission to do so. Employers and clients are frequently willing to grant permission to use imagery provided it does not divulge a trade secret or jeopardize confidential information.
Capturing imagery and preparing reports are two of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For more information on upcoming classes, call 609-239-4788 or visit us online at www.infraspection.com.
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A Hidden Danger in Electrical Systems
Tip written by: Infraspection Institute
Although thermography is a non-contact test, preparing for an infrared inspection of electrical equipment often requires manual preparation of switchgear components. Unwary thermographers and their assistants can be injured by making contact with cabinets or component surfaces that have become accidentally or unintentionally energized.
Switchgear enclosures and components are generally designed to prevent their surfaces from becoming energized. Under certain circumstances, switchgear enclosures and other dielectric surfaces can become unintentionally energized to significant voltage levels. This potentially lethal condition may be caused by improper wiring, faulty equipment, or contamination due to dirt or moisture.
The image below shows a potential of 265 volts AC between a molded case circuit breaker and ground. This condition was discovered after an unprotected worker received a shock by touching the phenolic breaker handle.
Whenever working on or near energized electrical equipment, keep the following in mind:
- Only qualified persons should be allowed near energized equipment
- Treat all devices and enclosures as though they are energized
- Never touch enclosures or devices without proper PPE
- Do not lean on or use electrical enclosures as work tables
- Always follow appropriate safety rules
- Know what to do in case of an accident
Remember ~
There are old thermographers and
There are bold thermographers; however,
There are no old, bold thermographers.
Thermographer safety is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online or call us at 609-239-4788.
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Gauging Solar Loading
Did you know that an automobile can be used to gauge solar loading? Under the correct conditions, a parked car can serve as a cheap, but effective, pyranometer.
Many types of infrared inspections rely on solar loading to heat the target so that infrared imaging may be performed successfully. Applications include, but are not limited to, low slope roof inspections, concrete bridge decks, storage vessel levels and latent moisture within building sidewalls. Ensuring that enough solar loading has occurred is imperative to collecting good data.
Good solar loading conditions are easy to recognize – long days with bright sunny skies, low humidity and no wind. More tricky is being able to determine if less than optimal conditions are allowing for appreciable solar gain.
A time tested method for gauging solar loading is to check the interior of a parked automobile. With the engine stopped and the windows and doors closed, allow the vehicle to sit in the sun for up to an hour. Immediately upon opening the door, check to see if the vehicle interior has exceeded outdoor ambient temperature. If a noticeable difference is not detected, feel the dashboard to see if it has warmed. If not, it is likely that appreciable solar loading has not occurred and it may be best to reschedule your solar driven inspection for another day.
Understanding the impact of environmental conditions on infrared inspections is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online or call us at 609-239-4788.
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NFPA 70E & Infrared Thermography
Tip written by: Infraspection Institute
On September 5, 2008, the eighth edition of NFPA 70E Standard for Electrical Safety in the Workplace became available superceding all previous editions. This latest edition of NFPA 70E contains several important changes and specifically addresses thermographic inspections of energized electrical systems.
Since 1979, the National Fire Protection Association has published the document, NFPA 70E. Since its initial publication, this safety standard has been renamed, expanded, and extensively revised. NFPA 70E is applicable to any workplace and is intended for use by employers, employees, and OSHA, among others.
The 2009 edition of NFPA 70E contains several changes over the 2004 edition. Among these changes are:
- Several key definitions have been revised
- Article 350 R&D Laboratories has been added to Chapter 3
- Chapter 4 has been deleted from the 2009 edition
- The 2009 edition contains an Introduction, 3 Chapters, and 15 Annexes
Perhaps the most significant change to NFPA 70E is that thermography is specifically addressed as a task. Table 130.7(C)(9) Hazard Risk Category Classifications provides Hazard/Risk categories ranging from 0 to 3 depending upon the type of equipment being inspected.
While Table 130.7(C)(9) may be used for certain tasks, it does not cover all inspection scenarios. For tasks not listed in Table 130.7(C)(9) or for power systems with greater than the assumed maximum short circuit current capacity or with longer than the assumed maximum fault clearing times, an arc flash hazard analysis is required.
The application and use of NFPA 70E are specifically covered within Infraspection Institute’s online short course, NFPA 70E – Are You in Compliance? Available 24 hours per day, this 45 minute course focuses on the history and application of 70E, changes included in the current edition, and how it applies to thermographers. For more information or to register, please visit: http://www.successiries.com/SuccessIRies_105.html.
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IR Inspections of Emergency Power Systems
Tip written by: Infraspection Institute
UPS systems and emergency generators are common defenses for facilities where uninterrupted electrical power is critical. Performed properly, IR inspections can help to improve reliability of emergency power systems.
Most facilities perform IR inspections of their electrical distribution systems at least annually as part of a PM program. To help ensure maximum reliability, regularly-scheduled IR inspections should also include the emergency power systems as well. When performing infrared inspections of emergency systems be sure to:
- Inspect all backup generators while running. Begin inspection at generator output leads and proceed to generator bus, breakers, and switchgear.
- Include all Automatic and Manual Transfer Switches. Inspect switches in both normal and emergency positions.
- Inspect UPS system controls, switchgear, battery cells, battery bus and wiring. Battery cell temperatures should be the same between cells with no hotspots on individual cells.
- Have adequate load on the subject emergency circuits This may be accomplished with normal facility load or by utilizing a load bank.
Taking the time to properly include your emergency power equipment in your IR inspection program can pay huge dividends by increasing the likelihood that your backup equipment won’t leave you in the dark should the power fail.
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Calculating Infrared Inspection Program Payback
Calculating savings and/or avoided costs is one of the most difficult tasks associated with an infrared inspection program; however, doing so is required in order to gauge how effective a program is.
In short, there is no way to calculate the exact value of the findings of an infrared inspection other than allowing the component run to failure and adding up the subsequent losses. Unfortunately, this is not a practical approach to maintenance.
As an alternative, there are several methods that professionals use to estimate program savings. A brief description of each of the most common methods is listed below:
1. Summary of Findings – A report comprised of the deficient items found during a given time period. Reports may be by the day, month, year, etc. This type of report does not provide any financial data.
2. Performance Effectiveness Ratios – Use accounting data to trend how an infrared inspection program impacts an overall maintenance program. Typically calculated for a single facility over an extended period of time. Improvements in efficiency can be compared to similar facilities or to the performance history subject facility.
3. Avoided Costs Method – A summary of the estimated cost of repairs for breakdown versus proactive repair efforts. Typically, proactive repairs are always cheaper since the outage can be planned and the cost of the actual repair is usually less since the subject equipment often suffers far less damage when not allowed to run to catastrophic failure.
4. Permanent Improvement Method – This is a summary of the financial impact on a given facility due to the implementation of an infrared inspection program. For example, infrared can be used to supplement a maintenance program by directing repair efforts to only those areas in need of attention rather than periodic application of labor-intensive manual work. In such cases, the cost difference between the two methods results in a savings every time the manual maintenance procedure is avoided in the future.
5. Statistics Based Method – This method is based upon insurance industry statistics associated with loss claims that have been paid to clients over a several year period. This method takes into account the value of the overall facility along with the severity of the problem. While this method is not as accurate as the Avoided Cost Method, it can be applied quickly and easily with a minimum of effort. Infraspection Institute’s Exception 2000™ software utilizes this method for calculating savings as one of its standard features.
Each of the above methods varies in the information provided as well as the ease of use and accuracy. We cover each method in depth in our Level III Certified Infrared Thermographer Course.
When calculating savings, we recommend that thermographers consult with their end user and choose one of the above methods that will best suit his/her needs and consistently apply the chosen method over time. While you will not be able to calculate savings exactly, you should obtain a good indication of the value of your program.
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Higher Resolution Imagers – What You Really Need to Know
The recent introduction of 640 x 480 pixel imagers has many thermographers speculating on the impact this equipment will have on our industry and their business. In this Tip we separate marketing hype from physics by revisiting the issue of resolution and its importance in thermal imaging.
Resolution is one of the most important objective specifications for a thermal imaging system. Due to a lack of standardization, this term is used in a variety of ways, many of which can be confusing or misleading.
Simply stated, resolution describes the capability of a thermal imager to clearly depict a target. Imager resolution is not solely dependent upon pixel count. Rather, it is determined by an interdependent set of circumstances, the most important of which are described below.
- Detector: Many manufacturers offer total pixel count of the detector as a measure of resolution. Resolution generally increases with the number of pixels; however, pixel viewing angle (IFOV) also affects detector resolution. Meaningful IFOV data are frequently unavailable.
- Optics: Lens quality affects an imager’s ability to clearly resolve a target at a given distance. With no industry standard for optics, lenses can vary widely between imagers.
- Signal-to-noise ratio: Generally, higher ratios equate to increased image resolution. Imagers with poor ratios will provide imagery that is grainy, thereby compromising image quality.
- Display Monitor: To maximize resolution, the pixel count of an imager display monitor should equal or exceed the number of detector pixels. Compact or monocular displays can severely limit resolution. Use of a high resolution monitor cannot compensate for low detector resolution.
When considering an imager for purchase, do not rely on pixel count as an accurate representation of imager resolution. Always try the imager under the same circumstances that you will encounter in the future. Because there is no objective method to determine imager resolution, one should physically compare subject imagers to each other and choose the one that meets their needs and budget.
To better understand imager resolution, read the article, Selecting, Specifying and Purchasing Thermal Imagers available from Infraspection Institute. To obtain a copy of the article, call 609-239-4788 or visit us online at www.infraspection.com.
