2014
January 06, 2014
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Cold Weather Clothing
Tip written by: Infraspection Institute
Cold weather clothing is a matter of functionality not fashion. Clothing needs to be worn in layers in order to trap air which is warmed by the body. When selecting clothing, start with the innermost layer and work outward. The use of multiple layers will trap warm air while providing greater ease of movement. As you add layers, be sure to adjust the next layer’s size accordingly.
The first layer should be made of a synthetic material that will wick perspiration away from the body and maintain its insulating properties when damp. The second layer is your main insulator and should be a breathable material that maintains its insulating properties when wet. Synthetic fleeces or natural wool are good choices. The outermost layer should be breathable and both wind and water resistant.
Head and neck protection is a must since nearly 40% of body heat is lost here. Perspiration is the main enemy of feet. The best footwear will have sturdy outers, good treads and a removable felt liner. Buy extra liners and replace them every few hours. Liners can take a full day to fully dry out so buy enough to get through a typical workday.
Mittens are the warmest but present problems in grasping tools etc. I have found that a heavy duty welder’s glove with cotton or wool gloves lining them provide good warmth and mobility. Buy enough liners to get you through the day. One final note, the body needs fuel to produce heat. Your calorie needs increase in cold weather and require regular replenishment with good wholesome foods.
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January 13, 2014
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Outsourcing IR Services
Tip written by: Infraspection Institute
Whether you are considering instituting an IR inspection program or already have one in place, obtaining competent manpower can be a challenge. One potential solution is to outsource services for additional manpower and expertise.
There are many factors that will determine if a person is capable of effectively supporting your infrared program. Your success in qualifying your thermographers can be increased if you keep the following in items in mind when qualifying individual thermographers.
- Proof of formal infrared training and certification level
- Amount of experience with the type(s) of inspections planned
- Experience with the selected test equipment
- Knowledge of the system(s) being inspected
- Documentation of requisite safety training
If you choose to outsource your thermographers through an infrared consulting firm, you may also wish to check the following.
- Number of years in business
- Type of infrared equipment to be utilized and calibration dates
- Insurance coverage
- Safety records and experience modification rating
- Professional references
Depending upon your company requirements, be sure the chosen vendor is capable of complying with security, background screening, and substance abuse policy requirements.
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January 20, 2014
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Air Travel With Your IR Imager
Tip written by: Infraspection Institute
While a thermographer is the most important part of any infrared inspection, no thermographer can get very far without a working imager. This week’s Tip includes some time-tested suggestions to ease air travel with an infrared imager.
Few experiences are more frustrating than traveling to a distant jobsite and discovering that your infrared equipment has been either delayed or damaged in transit. Such experiences can result in project delays or costly repairs.
When traveling by air, hand carrying your imager is the best way to help ensure that it will arrive with you and in good working order. Fortunately, most modern infrared imagers are sufficiently small to be treated as carry-on luggage. When hand carrying your imager on aircraft, keep the following in mind:
- Ensure that your imager’s carrying case does not exceed maximum size for carry-on luggage
- Be certain that your imager case does not contain prohibited items such as tools or pocketknives
- Ascertain the number of carry-on items that your chosen airline allows
- Expect potential delays when passing through security checkpoints due to additional screening
- Request security personnel take extra care when performing manual searches of your equipment or its cases
Lastly, be certain to check Customs regulations when traveling internationally. Many countries restrict the import/export of infrared equipment; others may require that an independent customs agent be hired to get expensive test equipment in/out of the subject country.
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January 27, 2014
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IR Thermography – A Game Changer for Home Inspections
Tip provided by: Robert J. Incollingo
Attorney at Law
856-857-1500
www.rjilaw.com
Recently there has been considerable debate among home inspectors regarding whether thermal imaging should be part of a home inspection. With prices for thermal imagers at an all-time low, thermal imaging may be poised to become an integral part of every home inspection.
A previously satisfactory explanation can be eroded by accumulating contradictory facts. When that happens, it’s time for a new explanation that takes into account all the facts, old and new alike. This giving way of an old world view in favor of a new one is called a paradigm shift. In my considered opinion, infrared thermography is driving a paradigm shift in the business of home inspection.
Home inspection is premised on general agreement that a home inspector is only responsible for describing defects which are readily apparent to visual inspection. This explanation is supported by observation that to ask otherwise of a home inspector would subject him or her to legal liability for unreported defects which may be undiscoverable in the absence of extraordinary and costly investigative measures beyond the budget of the ordinary home buyer. The business of home inspection would soon be out of business as a result.
The known variable in limiting the scope of home inspection is the cost of the additional inquiry. That is why a home inspector will often contract for additional investigation of specified defects which are not conclusively apparent to visual inspection, such as urea-formaldehyde, mold, and radon. Modern nondestructive technologies such as infrared thermography are changing the game, however, allowing for broadly applicable inspection techniques not limited to specific testing.
This one new fact – the affordability of thermography – contradicts the old world view of home inspection, because a visual inspection can now include the previously invisible infrared part of the spectrum at little additional cost. There is no longer a need to restrict the scope of inspection to the visible wavelengths. The potential benefits of the modern technology far outweigh the cost, when prorated across the useful life of the training and equipment required.
The law must and will in time follow the standards creep caused by the affordability of IR, and pull down the existing legal limitations of liability for home inspectors for unreported defects which could have been discovered with a handheld thermographic camera. In the near term look for the next step in the law that concerns home inspection: the case opinion that results in a regulation mandating written notice to consumers of the availability and utility of infrared thermography. Something as simple as a check-the-box notice on a pre-inspection agreement that an IR scan will/will not be provided should be the first step.
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February 03, 2014
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Preventing Falls in Icy Weather
Tip provided by Conoco Phillips
Numerous injuries result from slips and falls on icy sidewalks, parking lots, roads and other outdoor locations every year. Snow removal, sanding and salting of these type areas can help but, many times, total elimination of snow/ice hazards are impossible and other measures must be used to cope with these problems.
Focus on your walking path and pick steps that minimize or eliminate your exposure to icy slips. This is a time during which keeping your “eyes and mind on path” is more critical than ever.
Accept and anticipate the fact that you are at risk of falling at any given moment when walking on ice. Adjust your stride so your center of gravity is maintained as directly above your feet as possible by taking shorter steps than usual.
Don’t ignore the hazard presented by a slippery surface in your immediate path or work area. Take the time to spread sand, salt, or calcium chloride on icy areas and notify your Supervisor if further action is necessary. Keep in mind that salt (chloride) containing material is incompatible with stainless steel and is not to be used where contact can be made.
Footwear should have slip resistant soles. Avoid leather soled shoes. Equate this to driving a car with bald tires in the winter. You need something suitable to grip the surface you intend to walk on.
Wipe your feet off at the entrance of buildings so others won’t slip and fall on melted snow that has been tracked into the building.
Like the ice under your feet, beware of icicles over your head; they can be dangerous. Although you cannot stop them from forming, you can minimize their effects by controllably knocking them down.
Whether you’re dealing with an overhead or underfoot ice hazard, if you can’t control it, barricade or rope the area off.
When walking down stairs with or without an item in one hand, Safety In Motion has a technique that can reduce your chance of falling down the stairs. Grasp the handrail in the palm up position trailing behind you instead of your direction of travel. Your feet should be positioned at a slight angle toward that railing. Should you loose your balance, your grip on the handrail in this position will cause you to come to a stop against the handrail instead of falling down the stairs. Try the technique and become comfortable with it before you need it. Make protecting yourself a top priority!
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February 10, 2014
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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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February 17, 2014
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Infrared Training – Why it Isn’t All the Same
Tip written by: Infraspection Institute
With interest in thermography at an all-time high, more people are seeking training and certification. When comparing infrared course offerings, many mistakenly assume that all training and certification courses are the same.
The greatest limitation in an infrared inspection is the thermographer. Because of this, thermographer training and certification have long been recognized as requirements to help ensure accurate inspections. To this end, several firms offer Level I, II, and III training courses; however, these courses are not equal.
The American Society for Nondestructive Testing document, SNT-TC-1A outlines suggested topics for training and certifying NDT personnel in the Thermal/Infrared Testing Method. Suggested topics range from basic theory and camera operation to advanced thermographic applications. Since these topics are suggestions, companies have wide latitude in compiling course content. Because of this, one should never assume that courses bearing the same name will contain similar content.
When considering any infrared training course, be certain to:
- Review course curriculum carefully to ensure it meets your needs
- Ascertain type of certification provided and its expiration date
- Consider the history of the training firm and its credentials
Lastly, beware of training courses offered by equipment manufacturers or “vendor neutral” instructors. Only an independent training firm can offer unbiased opinions with respect to equipment choices.
For nearly 30 years, Infraspection Institute’s Certified Infrared Thermographer® training courses have set the industry standard for excellence. In addition to our Level I, II, and III Certified Infrared Thermographer® courses, we offer several industry-specific application and operator training courses. All courses are taught by field-experienced Level III practicing thermographers. For more information or to register for a class, call 609-239-4788 or visit us online at www.infraspection.com.
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February 24, 2014
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Why Imagers & Radiometers Disagree
Tip written by: Infraspection Institute
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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What Do Thermometers Measure?
Tip written by: Infraspection Institute
When asked what a thermometer measures, most people will tell you that thermometers measure whatever they contact. The correct answer is a little more complex and is fundamental to understanding and accurately applying contact thermometry.
Contact thermometry is a common technique used in temperature measurement. Thermocouples, resistance temperature devices, thermistors, and bulb thermometers are used to gauge the temperature of a wide variety of objects, materials, and systems. Although each works on a different principle, all contact temperature devices have one thing in common: contact thermometers report their own temperature.
Because contact thermometry is often used by thermographers to confirm radiometric measurements and to calibrate infrared equipment, accuracy is extremely important. To help ensure accuracy when using a contact thermometer, keep the following in mind:
- Select thermometer appropriate for task. Be sure to consider sensor size, thermometer sensitivity, operating range, and response time
- Prior to use, confirm that chosen thermometer is calibrated and operating properly
- Make certain that selected thermometer is in good contact with object
- Allow sufficient time for thermometer to achieve thermal equilibrium with object
Prior to using a contact thermometer, make certain that the surface to be measured is safe to touch. Never use a contact thermometer on energized electrical equipment or on any machinery where contact could result in personal injury.
Advanced heat transfer and temperature measurement are some of the many topics covered in the Infraspection Institute Level II Certified Infrared Thermographer® training course. For course schedules or to register for a course, visit Infraspection Institute online 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 motor temperatures are 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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Careful Testimony at Your Fingertips
Tip provided by: Robert J. Incollingo
Attorney at Law
856-857-1500
www.rjilaw.com
When called on to answer a question under oath, put your left hand on your lap, fingertips to your pant leg and think about the tip of your thumb. Your thumb reminds you that you have a predicate question of your own to answer for yourself, before you can even begin to reply to the other person. Counting on your thumb reminds you to ask yourself first, “Did I hear the whole question?” There are lots of reasons why you might not hear a question; your mind wanders, someone in the room speaks or coughs on top of the question, you don’t hear so well, outside traffic noise spikes, a distractingly pretty girl wanders past, or the inquirer mumbles in a heavy accent while covering his mouth with his hand. Maybe you were thinking of your thumb. If you didn’t hear the whole question, you cannot answer but to reply, “I didn’t hear the question. Could you please repeat it?”
If you did hear the question, your index finger should twitch. Your index finger is trying to remind you to ask yourself, “Did I understand the question?” There are lots of reasons why you might not understand a question; you don’t know a word, a word you know is being used in an unknown context, the question assumes a fact which is not true or not in evidence (of the “when did you stop beating your wife” variety), or the question is a leading question that incorporates a statement which it asks you to admit or deny, and as phrased you can do neither (such as, “You were wearing pants this morning when you hit my client, weren’t you?”). Sometimes, the question isn’t even a question, but a form of copspeak, a statement coupled with a pregnant pause. (Here your lawyer should jump in and state loudly for your benefit, “Objection as to form. No question pending.”) We must also admit the possibility that you are a dullard, the question is beyond you, and this whole business of questions reminds you unpleasantly of school.
If you didn’t truly understand the whole question, you must sensibly ask the questioner, “I didn’t understand the question. Could you please rephrase it?” Be prepared to get another question in return, “What part didn’t you understand?” Look blank for a meaningful second, and reply, “I’m not sure. If you rephrase it maybe I can answer.”
If you heard and understood the question, your middle fingertip will press against your leg, insistent that you ask yourself, “Do I know the answer? If not, is it because I don’t know the answer, or because I forget the answer?” This distinction makes much more of a difference on the stand than in regular life. If you knew something but forgot it, your recollection can be refreshed and introduced into evidence. If you never knew it, your testimony is not competent on this point, and is thus worthless forever. Sorry.
Should you reply, “I don’t know,” expect the follow-up question, “Well, who would know?” Look blank, and start on your thumb again. If you know who would know, say so and stop talking. Otherwise, feel free to say you don’t know who would know. They can’t mess with you this way.
Should you reply, “I don’t remember,” expect the follow up question, “Can you think of any documents which would tend to refresh your recollection?” Look blank, and start on your thumb again. And so on.
If you know the answer, your ring finger will tap and twitch to tell you that you are in the greatest danger of all. The pressure of your ring fingertip against your leg reminds you that you must answer the question truthfully in a manner that is only apparently helpful, and then stop talking. Answer only the question asked, which you are now presumed to have heard and understood, and coming to the very first period at the end of the very first sentence of your answer, stop talking. Stop talking. STOP TALKING. Do not answer the question you believe should have been asked; do not tell the questioner what you think she needs to know; do not answer a question with a question; do not object, or protest to your lawyer or the judge, “Do I have to answer that?”; do not preface your answer with an aside such as, “Can we go off the record for a minute here?” Instead, respond only to the question asked, as briefly and as generally as you can get away with, without obstructing justice. Do not blather, do not be helpful to the questioner, do not be funny, do not let your temper run away with you, do not lie. Answer in as few words as possible and then, you guessed it, stop talking.
And your little finger? Well, your little finger goes, “wee, wee, wee” all the way home. We thought you knew that.
Robert J. Incollingo, Esquire
4 Munn Avenue
Cherry Hill, NJ 08034
856-857-1500
www.rjilaw.com
Bob Incollingo is an attorney in private practice in New Jersey and a regular speaker at Infraspection Institute’s annual IR/INFO Conference.
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IR Inspections of Cool Roofs
Tip written by: Infraspection Institute
Energy and environmental concerns have caused many facility owners to look to their roofing systems for ways to conserve energy. Modern roofing systems known as ‘cool roofs’ can provide savings; however, they can present challenges for thermographers who inspect them.
Over 90% of roofs in the United States are dark colored. On sunny days, temperatures of these roofs can reach 150º to 190º F causing decreased indoor comfort, increased cooling costs, and premature aging of roofing materials. Advances in roofing technology have led to the development of ‘cool roof’ systems that help to solve these challenges.
Cool roof materials have a high solar reflectance or albedo. Compared to conventional roof materials, cool roofs operate at lower temperatures since they absorb less energy from the Sun. Cool roofs also have a high thermal emittance enabling them to radiate well and shed heat quickly after sunset.
Cool roof membranes are usually made of single-ply rubber or plastic materials such as EPDM, PVC, and TPO. These materials are usually white in color and have a smooth surface. Cool roof coatings or paints are an alternative for existing low-slope roofs.
Although cool roof materials are rated to have a high emittance, thermographers should remember that this value is an average emittance value calculated in a laboratory under ideal conditions and at a perpendicular viewing angle. During an infrared inspection, smooth-surfaced roofs appear quite reflective to a thermal imager due to the low viewing angle that is usually associated with inspections performed on foot from the roof surface. This condition is most severe on cloudless nights when atmospheric humidity levels are low.
Due to the low emittance associated with smooth roof surfaces, thermographers can easily miss the small temperature differentials associated with latent moisture. In order to mitigate errors associated with low emittance, thermographers should choose a short wave (2 to 5.6 microns) thermal imager whenever inspecting a smooth-surfaced roof regardless of membrane color or material.
Infrared inspection of flat roofs and proper equipment selection are two 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 Infraspection Institute or call us at 609-239-4788.
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Safety – It Takes Two
Tip written by: Infraspection Institute
If you are a thermographer who performs infrared inspections of electrical distribution systems, you are not alone and you never should be. Working alone near exposed, energized electrical equipment is not only dangerous, it is a violation of federal law!
Administered by OSHA, the Occupational Safety and Health Standards for General Industry, 29 CFR, Part 1910 apply to most thermographers working within the United States or its territories. Specifically, 1910 Subpart R covers the operation and maintenance of electric power generation, control, transformation, transmission and distribution lines or equipment. Covered facilities include utilities and equivalent industrial establishments.
According to Subpart R, prior to the commencement of work, medical and first aid supplies must be provided for, including persons trained in first aid and CPR when work is on or near exposed lines or equipment energized at greater than 50 volts. Since CPR cannot be self-administered, at least two people trained in first aid and CPR must always be present when working near most exposed energized equipment.
When performing infrared inspections in the future, having a second CPR trained person along will not only satisfy OSHA requirements, it may save your life should an accident occur!
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Inspecting Shaded Building Elevations
Tip written by: Infraspection Institute
Infrared inspections of building exteriors often rely on solar loading to create temperature differentials necessary to detect damage or defects. A common challenge for thermographers is inspecting building elevations that do not receive direct sunlight.
Infrared imaging is a proven technique for testing building sidewalls. Inspecting buildings during evening hours following a sunny day can reveal the presence of structural details, missing or damaged insulation, or latent moisture. These conditions are detectable due to changes in the thermal capacitance or conductance of the walls.
When using solar energy to drive an infrared inspection of building sidewalls, it is normal for a building to heat unevenly. Typically, east elevations receive the least direct sunlight, while the south and west elevations receive the most. For many northern latitudes, north elevations do not receive direct sunlight.
Fortunately, it is not necessary to receive direct sunlight in order to drive an infrared inspection. Provided that the building is not in close proximity to other structures or heavily shaded areas, it will receive indirect heating from nearby objects such as the ground. For elevations that are heated indirectly, it is important to note that they will exhibit weaker thermal patterns when compared to other exposures that receive direct sunlight.
When using solar loading to drive an infrared inspection, keep the following in mind:
- Choose an evening when weather conditions are optimal – sunny day followed by a cool clear evening with no wind
- Begin infrared inspection on the North elevation and continue in a clockwise fashion around the exterior of the building
- Depending upon wall construction, type of defect, and local weather conditions, it may be necessary to begin prior to sunset
Lastly, be aware that thermal patterns associated with defects may only appear for a short period of time on the North and East elevations. All thermal anomalies should be investigated for cause and appropriate action taken.
Infrared inspection of building envelopes is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training including course locations and dates, visit us online at www.infraspection.com or call us at 609-239-4788.
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Thermal Imager Rental – A Smart Alternative
Tip written by: Infraspection Institute
With prices ranging to over $10,000, a thermal imager can represent a considerable investment. For companies getting started in thermal imaging, renting an imager can provide a cost effective alternative to purchasing a system outright.
Whether you are facing an equipment shortage or looking to evaluate the characteristics of a new imager prior to purchase, renting a thermal imager may provide a solution. In some cases, imager manufacturers will credit short term rental fees toward the purchase price of an imager. As with purchasing an imager, there are several important things to consider when arranging for a rental unit.
To help ensure that you select an appropriate imager for rental, be certain to:
- Identify appropriate spectral response required for project
- Determine if temperature measurement is required
- Evaluate the system for objective specifications
- Ascertain imager compatibility with reporting software
When arranging for a rental, obtain terms and conditions from the rental agency. These should include, but not be limited to: rental period, extension of rental, shipping costs, and requirements for insurance against loss. One should also consider the rental agency’s ability to provide technical support during the rental period.
For more information on choosing an infrared imager, refer to the article, “Selecting, Specifying, and Purchasing a Thermal Imager” available as a free download on this website.
Lastly, the greatest limiting factor in any infrared inspection is the thermographer. For accurate results, infrared inspections should only be performed by properly trained and certified thermographers. For more information on thermographer training and certification, please contact Infraspection Institute.
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Infrared Imaging and Spray Testing of Walls
Tip written by: Infraspection Institute
Infrared imaging can be useful for detecting leaks within building sidewalls; however, timing an inspection can be tricky. Controlled wetting of walls can be used to simulate storm conditions during an inspection.
Water spray racks are mechanical devices that permit controlled wetting of a building surface. Spray racks typically consist of lightweight tubing and engineered spray heads spaced at regular intervals. When connected to a water supply and placed in front of a building wall, a spray rack can be used to deliver a deluge of water to an area of interest. The amount of water delivered can be controlled by using different size spray heads and/or varying supplied water pressure.
Spray racks are commonly used for testing the water tightness of curtain walls. During an infrared inspection from the interior of a building, spray racks can provide continuous wetting of walls to aid in leak detection. Spray racks can also be used to uniformly saturate a wall when infrared inspections are to be performed at a later time to detect evidence of latent moisture.
after sunset; building imaged from exterior
Because spray rack operation requires special tools and presents unique challenges, it is often best done by a qualified professional. Thermographers performing imaging during or after spray testing should keep the following in mind:
- Spray testing can be time consuming due to set up and/or repositioning of spray equipment
- Spray testing can cause significant building leakage requiring an interruption of testing
- Spray testing can be messy; avoid getting your imager wet
- When imaging from the exterior of a building, allow sufficient time for surface to dry and a Delta T to develop
Thermal imaging during spray testing is one of several applications covered in the Infrared Inspections for Home & Building Inspectors training course. For more information call 609-239-4788 or visit us online at: www.infraspection.com
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Protecting Yourself in the Sun – Part 1
Tip excerpted from: www.osha.gov
With the height of Summer, many thermographers focus their attention on the discomfort associated with heat and humidity. Those who spend time outdoors should also be aware of the health hazards associated with unprotected exposure to the Sun.
Sunlight contains ultraviolet (UV) radiation, which causes premature aging of the skin, wrinkles, cataracts, and skin cancer. The amount of damage from UV exposure depends on the strength of the light, the length of exposure, and whether the skin is protected. There are no safe UV rays or safe suntans.
Following a few simple tips can help protect you from the harmful effects of UV radiation.
- Cover up. Wear tightly-woven clothing that blocks out light. Try this test: Place your hand between a single layer of the clothing and a light source. If you can see your hand through the fabric, the garment offers little protection
- Use sunscreen. A sun protection factor (SPF) of at least 15 blocks 93 percent of UV rays. You want to block both UVA and UVB rays to guard against skin cancer. Be sure to follow application directions on the bottle.
- Wear a hat. A wide brim hat (not a baseball cap) is ideal because it protects the neck, ears, eyes, forehead, nose, and scalp.
- Wear UV-absorbent shades. Sunglasses don’t have to be expensive, but they should block 99 to 100 percent of UVA and UVB radiation.
- Limit exposure. UV rays are most intense between 10 a.m. and 4 p.m. If you’re unsure about the sun’s intensity, take the shadow test: If your shadow is shorter than you, the sun’s rays are the day’s strongest.
For more information on this topic or on other workplace safety and health issues, visit www.osha.gov.
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Protecting Yourself in the Sun – Part 2
Tip excerpted from: www.osha.gov
Most people have experienced the discomfort of sunburn at one time or another. Few tend to realize that unprotected exposure to the Sun increases one’s risk of developing skin cancer which can be fatal. Early detection is your first line of defense in treating skin cancer.
Sun exposure at any age can cause skin cancer. Be especially careful in the sun if you burn easily, spend a lot of time outdoors, or have any of the following physical features:
- Numerous, irregular, or large moles
- Freckles
- Fair skin
- Blond, red, or light brown hair
It’s important to examine your body monthly because skin cancers detected early can almost always be cured. The most important warning sign is a spot on the skin that is changing in size, shape, or color during a period of 1 month to 1 or 2 years.
Skin cancers often take the following forms:
- Pale, wax-like, pearly nodules
- Red, scaly, sharply outlined patches
- Sores that don’t heal
- Small, mole-like growths – melanoma, the most serious type of skin cancer
If you find such unusual skin changes, see a health care professional immediately. For more information about preventing, detecting, and treating skin cancer, check out these sources:
American Cancer Society www.cancer.org
Centers for Disease Control and Prevention www.cdc.gov/ChooseYourCover
The Skin Cancer Foundation www.skincancer.org
For more information on this topic or on other workplace safety and health issues, visit www.osha.gov.
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Infrared Inspection of Capacitors
Tip written by: Infraspection Institute
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.
Thermogram shows left capacitor operating at ambient temperature. This condition is typical of an open supply circuit or failed capacitor winding
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:
1. Visually inspect capacitor bodies. Capacitors should not be misshapen or swollen.
2. Thermographically inspect capacitor bodies. Capacitors should be warmer than ambient air temperature and exhibit equal temperatures across all phases.
3. 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 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.
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A Bird’s Eye View
Tip written by: Infraspection Institute
When performing infrared inspections of large structures or systems, it is often difficult to see “the big picture”. For some systems, performing an infrared inspection from an aircraft may provide a solution.
Large structures such as industrial roofs, buried steam systems and pole-mounted electric power lines can be difficult and time consuming to inspect from the ground. Often, a thermographer’s field of view is limited to a small portion of the subject system making qualitative comparisons more difficult. For systems spread over a wide geographic area, maneuvering over the ground can require a considerable amount of time.
An alternative to ground-based infrared inspections is to perform them from an aircraft. Airborne infrared inspections provide a macro view of the subject system and can reduce inspection time by eliminating ground-based obstacles.
Both fixed-wing aircraft and helicopters can be used as platforms for conducting an aerial infrared inspection. Infrared inspections may be conducted utilizing a hard-mounted infrared imager or, in some cases, a portable imager aimed through an open window or doorway. When selecting an infrared imager for a specific project, keep the following in mind:
- Amount of resolution required for clear imagery at altitude
- Compatibility of imager with aircraft type
- Imager’s ease of use from within an aircraft. For lengthy projects, remote-controlled, fixed-mount imagers provide less stress for a thermographer.
Due to the logistics and costs associated with aerial infrared inspections, one may wish to consider hiring an experienced consultant who specializes in aerial infrared inspections.
Performing infrared inspections from aircraft is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on open enrollment classes or our Distance Learning program, visit us online or call us at 609-239-4788.
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Grilling Safety Tips
Tip provided by the National Fire Protection Association
With Summer upon us, many will return to outdoor cooking on a regular basis. In this Tip we offer important safety considerations for all outdoor chefs.
There’s nothing like outdoor grilling. It’s one of the most popular ways to cook food. But, a grill placed too close to anything that can burn is a fire hazard. They can be very hot, causing burn injuries. Follow these simple tips and you will be on the way to safe grilling.
- Propane and charcoal BBQ grills should only be used outdoors
- The grill should be placed well away from the home, deck railings and out from under eaves and overhanging branches
- Keep children and pets away from the grill area
- Keep your grill clean by removing grease or fat buildup from the grills and in trays below the grill
- Never leave your grill unattended
Charcoal grills
- There are several ways to get the charcoal ready to use. Charcoal chimney starters allow you to start the charcoal using newspaper as a fuel.
- If you use a starter fluid, use only charcoal starter fluid. Never add charcoal fluid or any other flammable liquids to the fire.
- Keep charcoal fluid out of the reach of children and away from heat sources
- There are also electric charcoal starters, which do not use fire. Be sure to use an extension cord for outdoor use
When you are finished grilling, let the coals completely cool before disposing of them in a metal container.
Propane grills
Check the gas tank hose for leaks before using it for the first time each year. Apply a light soap and water solution to the hose. A propane leak will release bubbles. If your grill has a gas leak, detectable by smell or the soapy bubble test, and there is no flame, turn off the gas tank and grill. If the leak stops, get the grill serviced by a professional before using it again. If the leak does not stop, call the fire department. If you smell gas while cooking, immediately get away from the grill and call the fire department. Do not move the grill.
If the flame goes out, turn the grill and gas off and wait at least 15 minutes before re- lighting it.
Download these NFPA safety tips on grilling
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Making Your Own Blackbody Simulator
Tip written by: Infraspection Institute
Blackbody simulators are essential tools for checking the calibration of infrared imagers and radiometers. One alternative to purchasing a blackbody simulator is to make your own.
In order to provide accurate temperature values, infrared imagers and radiometers must be calibrated on a periodic basis. During the calibration process, blackbody simulators provide targets with a known temperature and a known emittance.
Thermographers wishing to perform a calibration check of their instruments may elect to purchase a blackbody simulator. Several models are commercially available with prices ranging up to several thousand dollars. As an alternative, thermographers may elect to make their own simulator from commonly available items. This may be accomplished as follows:
- Procure a 2 liter square metal can and a 60 Watt electric aquarium heater. Can opening must be large enough to allow heater to be inserted into can opening.
- Cover the exterior of the can with Scotch #191 PVC electrical tape.
- Fill the can with water to within 1” of the top and insert aquarium heater. Avoid causing can to overflow.
- Energize heater and set to desired temperature. Be certain to allow sufficient time for can temperature to stabilize.
When performing a calibration check of infrared equipment, set the subject radiometer’s emittance control to 0.97. Ascertain the can temperature using a thermocouple. Compare the two values and note any differences.
Lastly, be certain to work safely. In particular, avoid fully immersing any aquarium heater not designed for immersion. Be certain to disconnect the aquarium heater from its power source and allow it to cool prior to removing it from the can.
Equipment calibration is one of the many topics covered in the Level II Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training including course locations and dates, visit us online at www.infraspection.com or call us at 609-239-4788.
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Gauging Solar Loading
Tip written by: Infraspection Institute
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.
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Infrared Inspections of Conveyor Bearings
Tip written by: Infraspection Institute
If your facility utilizes conveyor systems for moving product, you may be able to use your thermal imager to locate defective bearings.
Many conveyor systems utilize a large number of rolling element bearings to support rollers or conveyor belting. Depending upon the size of the facility, a conveyor system may contain thousands of rolling element bearings. Due to the vast number of bearings, inspecting them can be an enormous and time consuming task.
Because bearing wear is usually accompanied by a rise in temperature prior to failure, infrared imaging can be used to detect overheating bearings. The infrared inspection is performed by comparing similar bearings under similar load. Bearings appearing inexplicably warm can be noted for further investigation.
When performing your infrared inspection, bearings should be operating at normal speed and you must have line-of-sight access to the subject bearings. Since the infrared inspection is performed from ground level without special preparation, the inspection can be performed quickly.
When performed by an experienced, certified thermographer, infrared inspections can provide a cost effective method for helping to eliminate unexpected failures and improving your production uptime.
Infrared inspection of bearings 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 Infraspection Institute or call us at 609-239-4788.
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Frequency of IR Roof Inspections
Tip written by: Infraspection Institute
The benefits of thermography for condition assessment of insulated roofs are well documented. Performed on a regular basis, infrared thermography can help to extend the overall life of a roofing system when utilized as part of a preventive maintenance program.
As a building component, roofing systems tend to be out-of-sight and out-of-mind. Despite the critical role they play in keeping a facility dry, many roofs garner little attention until they begin to leak. In order to minimize damage, it is imperative that roof leaks be detected and repaired at an early stage.
Many roofs can gain significant quantities of moisture in a very short period of time. In the case of retrofitted roof systems, whole roof sections can become saturated in a matter of weeks while leaking little or no water into the occupied spaces. By the time a roof leak is noticed within the building, replacement may be the only option available.
For best results, insulated roofs should be thermographically inspected at least twice per year (e.g. Spring and Autumn) in accordance with published standards and guidelines. Semi-annual infrared inspections can help to identify new areas of moisture damage and help to ensure that recent repairs are performing in a watertight manner. Infrared findings should be correlated with a thorough visual inspection and other pertinent data to formulate an effective roof maintenance strategy.
Infrared inspection of flat roofs is one of the many topics covered in all Infraspection Institute Level I training courses. For more information on thermographer training or to obtain a copy of the Standard for Infrared Inspections of Insulated Roofs, visit Infraspection Institute or call us at 609-239-4788.
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Inductive Heating Hotspots
Tip written by: Infraspection Institute
Loose connections, overloading and imbalanced loads cause overheating of components within an electrical system. Depending upon construction and operation of the electrical system, a perplexing and possibly serious condition called inductive heating can cause non-current carrying components to overheat.
As current flows through an electrical circuit, a magnetic field forms around the conductor. When current flow is high, a strong magnetic field can develop and extend for several inches around the subject conductor(s). If ferrous materials such as steel are positioned within this magnetic field, they can heat up even though they are not part of the circuit.
Inductive heating can occur on bus supports, cable tray fasteners, bushing skirts and switchgear enclosures. Affected components can become hot enough to cause significant heat damage or even skin burns. The temperature of the affected component will depend upon the strength of the magnetic field, and the composition and location of the affected component.
Because inductive heating can cause components to reach temperatures of over 200ºF, thermographers should pay particular attention whenever combustible materials or dielectric insulation are located near, or in contact with, an inductively heated item.
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.
