2015
January 05, 2015
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Storing & Transporting Your IR Equipment
Tip written by: Infraspection Institute
Among thermographers, few things can cause an acute stomach ache like damaged equipment. Damaged equipment is not only costly to repair, but may also interrupt an inspection program while the equipment is being repaired.
With infrared equipment, an ounce of prevention is worth several pounds of cure. Fortunately, preventing equipment damage is easy and inexpensive. Some of the best ways to prevent damage are as follows:
- Store IR equipment in hard sided shipping cases that have die cut foam to fit the subject equipment and its accessories
- Keep lens caps on camera and extra lenses while in the storage case
- When not in use, store IR equipment and accessories in a cool, dry place
- When transporting or shipping equipment, utilize extra padding to prevent components from shifting in the carrying case
- When traveling on an aircraft, hand-carry your imager. Be sure to allow extra time when going through airport security and encourage inspectors to be extra careful with your equipment
Lastly, maintain your equipment carrying cases in good working order. Repair or replace defective or worn hardware. If your case should become worn, replace it with a new original or an after-market case suitable to the task. Some shipping cases are guaranteed for life and replacement parts may be available at no charge.
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January 12, 2015
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Protecting Yourself from Hydrogen Sulfide
Tip written by: Infraspection Institute
Petrochemical refineries provide many opportunities for the application thermography. At the same time, they also provide unique safety challenges. In this Tip we discuss safety issues when working around hydrogen sulfide.
Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a “rotten egg” smell. It occurs naturally in crude petroleum and natural gas, and can be produced by the breakdown of organic matter and human/animal wastes such as sewage. Large quantities of hydrogen sulfide are often produced in refineries. Unintended leaks can allow hydrogen sulfide to collect in low-lying and poorly ventilated areas such as basements, manholes, sewer lines and underground telephone/electrical vaults.
Hydrogen sulfide can be smelled at low levels, but with continuous low level exposure or at higher concentrations you lose your ability to smell the gas even though it is still present. At high concentrations one’s ability to smell the gas can be lost instantly. NEVER depend on your sense of smell for indicating the continuing presence of this gas or for warning of hazardous concentrations.
The health effects associated with exposures to hydrogen sulfide vary with how long, and at what level, you are exposed. Asthmatics may be at greater risk. At low concentrations, hydrogen sulfide can cause irritation of eyes, nose, throat, or respiratory system. At high concentrations, shock, convulsions, coma, and death are possible; in some cases the effects can occur within a few breaths.
Before entering areas with possible hydrogen sulfide, the air should be tested for the presence and concentration of hydrogen sulfide by a qualified person using appropriate test equipment. Testing should also be performed to determine if fire/explosion precautions are necessary. If hydrogen sulfide or hazardous gasses are present, the space should be ventilated until acceptable limits are achieved. In some cases, continuous monitoring of the work area may be required.
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 at www.infraspection.com or call us at 609-239-4788.
For more complete information on workplace safety, visit the OSHA Website.
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January 19, 2015
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Build It & They Will Come
Tip written by: Infraspection Institute
Build it and they will come. This romantic notion worked for Kevin Costner in the film, Field of Dreams; however, real life and business are rarely that simple. Once you have built your infrared inspection business, there are time-tested ways to help ensure that customers will come.
Getting prospects to come to your business involves more than setting up shop and hanging out a shingle. In order to thrive, you have to let prospects know that you are open for business and that you are ready to respond to their needs. The following are some of the most effective ways to get your message out to potential customers.
- Have a professional artist design a color brochure that fully describes your capabilities and strengths along with the benefits that customers can expect from your services.
- Engage a website professional to design a website that mirrors your advertising brochure. Whenever possible, choose a domain name that is easy to remember and contains your company name only. Be certain to update your website periodically.
- Network with other professionals that can bring you work through their business activities.
Architects, engineers, contractors and consultants can be excellent strategic partners. Once you have established a relationship, you reap the benefit of their sales efforts at no cost.
- Once you have identified prospects within your region, hit the bricks and do some old fashioned selling. In this day of internet selling, email and instant messaging, putting a human face on your company can be worth its weight in gold.
Lastly, advertise your company in an online directory where prospects are likely to visit. At present, IRINFO.ORG receives 250,000 visitors each year, many of whom are looking to hire an infrared professional. Listing your company in our Directory of IR Inspection Companies can mean the difference between working hard or hardly working.
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January 26, 2015
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Air Travel with Your IR Imager – Part 2
Tip suggested by: Peter Plein, Certified Infrared, Inc.
To help ensure proper handling of their equipment, most thermographers who travel by air opt to hand carry their imagers. Proper planning and preparation can help avoid delays when passing through security checkpoints.
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:
- Ascertain the number of carry-on items that your chosen airline allows
- 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, pocketknives, or liquids
- Check Customs regulations prior to international travel; some countries restrict import/export of infrared cameras and/or expensive test equipment
- Expect potential delays when passing through security checkpoints due to any additional screening that may be required
Lastly, be aware that contaminants from industrial environments can cause positive test results during explosives screening. Should your equipment test positive during screening, remain calm while security personnel sort things out. Since this can take some time, it is possible that you will miss your scheduled flight, particularly if you are on a tight schedule.
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February 02, 2015
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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. Capacitors should be warmer than ambient air temperature and exhibit equal temperatures across all phases.
- Check bushing and wiring connections for hotspots.
Images courtesy Dan Playforth.
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.
February 09, 2015
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Using a First Surface Mirror
Proper conduct of an infrared inspection requires line of sight access to the object(s) being inspected. A first surface mirror can often be utilized to inspect components that may be obstructed or obscured.
A first surface mirror is a special optical mirror that has a highly reflective coating adhered to the front of the mirror substrate. For infrared inspections, first surface mirrors can be temporarily utilized as reflectors to inspect areas that are inaccessible or unsafe for a thermographer to enter.
When using a first surface mirror with your infrared imager, keep the following in mind:
- Select a mirror of sufficient size for the selected imager and target
- Inspect mirror prior to use for cleanliness and condition
- Place the mirror in the optical path between the imager and object being inspected
- Position the mirror so that the reflective side of the mirror faces the imager
- Inspect object by imaging mirror surface
First surface mirrors are commercially available from a number of scientific suppliers that deal with optics and lasers. When using a first surface mirror, be certain to follow necessary safety precautions, especially when working near energized electrical components.
The use of first surface mirrors and proper inspection techniques are two of the many topics covered in all Infraspection Institute Certified Infrared Thermographer® training courses. For more information on open enrollment classes or our Distance Learning courses, call 609-239-4788 or visit us online at infraspection.com.
February 16, 2015
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Begin With the End in Mind
“Begin with the end in mind” is a frequent quotation from Stephen Covey’s best selling book, The 7 Habits of Highly Effective People. Applying this principle can have a dramatic impact on many things including an infrared inspection program.
Prior to undertaking any task or project, it is important to have a clear understanding of what the final outcome should be. With this vision in mind, one is able to gauge the effectiveness of their efforts in achieving goals. By beginning with the end in mind, one knows what the goals are and can help chart a course of action that leads directly to these goals.
Building an infrared inspection program is like a construction project. You need to have a clear understanding of what you desire when construction is completed. When starting an infrared inspection program, decide what you want from your program. This is best done by asking yourself the following questions:
- What is the role of thermography – PPM, PdM, QA, or Condition Assessment?
- Which systems/equipment do I want to inspect?
- How will thermography improve operations – decrease unscheduled downtime, improve product quality, and reduce production losses?
- What data are available for measuring the program’s effectiveness?
Once these questions have been answered, one can begin to set up an infrared inspection program with necessary equipment, staff, and support personnel. By beginning with the end in mind, an infrared inspection program is more likely to succeed by providing value and producing measureable results.
Designing an effective infrared inspection program is one of the many topics covered in the Infraspection Institute Level III Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online at www.infraspection.com or call us at 609-239-4788.
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February 23, 2015
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Frostbite & Hypothermia
Tip written by: Infraspection Institute
“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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The Power of Inductive Heating
The magnitude and intensity of inductive heating should not be underestimated when performing infrared inspections of electrical switchgear. Inductive heating is derived from the proximal interaction of non-current carrying devices with the magnetic field around energized conductors that are under load.
Inductive heating affects ferrous metals and causes inexplicable heating of non-current carrying components. The intensity of heating is a function of the amount of current passing through the conductor and rather than the voltage class. In some cases, the affected components can reach temperatures in excess of several hundred degrees.
During a recent inspection at a power generation plant, two examples of inductive heating where observed near the plant’s step-up transformers. Images captured showed intense heating on a non-current carrying support pole and bus transition box, both of which were close to iso-phase bus entering a13kV to 230kV step-up transformer. Temperatures documented on these devices were in excess of 400°F. Being the starting point of transmission service, a heavy current load would be expected on energized equipment.
Often, engineering designs on switchgear enclosures and other electrical equipment do not take into consideration the interaction of non-current carrying ferrous devices within electro-magnetic fields. In some cases, these situations can pose safety hazards when the affected component is in contact with combustible materials or heats structures that are accessible to human contact. When faced with perplexing heat patterns on components that should not be hot, inductive heating may be to blame.
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Defining Ambient Temp
Tip written by: Infraspection Institute
Ambient temperature is a term which appears in nearly all thermographic reports. However, many thermographers define ambient differently. Some define it as room air temperature while others define it as the temperature inside of the component enclosure.
According to the IEEE, for electrical components ambient temperature is the environmental temperature immediately surrounding the subject component. For devices located within enclosures, this is the temperature within the enclosure while it is closed and operating. For components in free air, it is the temperature surrounding the component.
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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Imager Operational Check Prior to Inspections
Many infrared applications standards require that infrared test equipment be within calibration prior to the conduct of an inspection. Although performing a full calibration on daily basis is impractical, performing some simple operational checks can help to ensure that equipment is functioning properly.
Prior to commencing an infrared inspection, a thermographer should set up his/her equipment by:
- Checking imager optics for cleanliness
- Ensuring that batteries are fully charged
- Inspecting power and video cables/connectors for electrical integrity
- Allowing imager to stabilize with ambient temperature.
After completing the above, power-up the thermal imager and note that the imager initializes properly. Once the imager has initialized, adjust imager controls to normal temperature range. Focusing on a high emittance target such as a tabletop or a wall covered with latex paint, check the monitor for image clarity. If the image has inexplicably hot or cold pixels, perform a non-uniformity correction.
Once the image appears clear, a small Delta T can be created by placing one’s hand on one of the above high E surfaces for a few seconds. After removing the hand, image this same area and note the thermal pattern and its intensity. With a properly operating thermal imager, the thermal pattern of the hand should be clearly visible and last for at least one minute.
For more information on thermographer training and certification, contact Infraspection Institute at 609-239-4788 or visit us online at www.infraspection.com.
March 23, 2015
Tip provided by Wayne Swirnow
IR Image Capture & Tuning
A Thermographer is like a professional photographer – both communicate a message about their subjects through imagery. Similar to photography, focus, composition, and exposure of thermograms are important since they are often the main vehicle that a Thermographer uses to convey information.
The following tips will help ensure the quality of thermal images:
- Ensure that the image is in focus. High pixel count imagers are still “low resolution” compared to even the lowest cost daylight cameras. Typical infrared images may not seem very “clear” to an end user who has no experience interpreting thermograms. Capturing images which are even slightly out of focus will degrade their clarity and can compromise the accuracy of radiometric data embedded within the thermogram.
- Show your target as large as safely practical. Ideally, the target should fill up a significant portion of the imager’s display screen. Select an imaging distance and lens to ensure that the target is big and clear in the imager’s viewfinder. By using the maximum amount of pixels across the target, you provide the best optical and thermal resolution and minimize measurement errors due to spot size limitations.
- Adjust imager Level and Gain settings to provide the most dynamic range of color for the object. Adjust the imager to use most of the color on the object and limit how much color is used for the background unless it is important to also show some background information. This approach will give images the best contrast while conveying the most thermographic information to the recipient of the report.
There are many philosophies of how to best thermally tune images and one may be more appropriate than another depending on the application and what the Thermographer is trying to show the end user. One approach is to treat tuning as a dynamic element, tuning for each image taken. Another is to tune all images the same so a large set of images all have the same temperature span which makes them easier to compare when viewed as a set.
For instance, if a specific exception within a structure’s wall is the target, tuning the image to best show that local area of interest may be appropriate. An example of this would be to tune the image so that the details of an insulation void within a wall, or a thermal bridging element are well defined using the most amount of colors across the smallest temperature span to clearly illustrate the exception. However, if the task is to image a side of an entire building then you may choose to sacrifice some local thermal contrast to achieve a more uniform presentation down the length of a building wall by tuning all images to the same span and level.
For a comprehensive report of a building you may need both globally tuned lower dynamic range images taken sequentially down the side of a building and high dynamic images of specific areas on that wall and which have been finely tuned to best show that particular exception.
In electrical work, each image is typically tuned for a specific target. In this application, it is critical to finely tune the image such that it is possible to see from where heat is being generated in a group of connections or components.
The job of the Thermographer is to locate exceptions and present them to the end user through report imagery. Images which are clearly focused, well-composed, and properly tuned for will convey the most information and require the least amount of explanation.
IR Inspections of Timber Framed Buildings
Tip written by: Infraspection Institute
Well known for its ruggedness and distinct architectural features, timber frame construction is a popular choice for commercial and residential buildings. Used properly, thermal imaging can be used to detect evidence of excess energy loss within these unique structures.
Timber framing is a building construction method that utilizes heavy, squared-off timbers rather than dimensional lumber such as 2x4s. Timbers are carefully fitted and secured using mortise-and-tenon joints often held together by large wooden pegs. The use of timber framing was common for wooden buildings constructed in the 19th century and earlier.
When utilizing timber frame construction for conditioned buildings, particular attention must be paid to the construction of exterior walls and the roof to minimize air leakage. Failure to do so can result in significant comfort and performance issues. The dark areas in the thermal image below are the result of significant air leakage within a timber framed building.
In addition to detecting air leakage sites, thermal imaging can also reveal energy loss due to missing, damaged, or misapplied insulation. The thermal image below shows an exterior wall and roof of a timber framed building where traditional framing was used for sidewall and roof construction. The dark areas show significant energy loss.
For best results, thermal imaging of timber framed buildings should be performed from the inside of the building when there is an inside/outside temperature differential of at least 10 Celsius (18 F) degrees. Thermal imaging may be performed under natural conditions or while the building is depressurized. Imaging should be scheduled to avoid errors due to solar loading of the building’s walls and roof.
Infrared inspections 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 or to obtain a copy of the Standard for Infrared Inspection of Building Envelopes, visit us online at www.infraspection.com or call us at 609-239-4788.
Measurement Accuracy Specifications
Tip written by: Infraspection Institute
“A man’s got to know his limitations.” Clint Eastwood popularized this quote in a 1972 film; this sage observation can also be applied to infrared equipment.
When stating the potential accuracy of infrared thermometers, many manufacturers state radiometer accuracy as “± 2%”. The significance of this specification is often poorly understood causing many to overestimate the accuracy of non-contact temperature measurements.
An accuracy statement of “± 2%” is actually an abbreviated statement. The full statement is “± 2% of target temperature or 2º C, whichever is greater”. The full statement is required since measurement accuracy generally decreases with lower temperature targets. Furthermore, an accuracy of “± 2%” would place accuracy at 0% when measuring targets operating at 0º!
When considering an accuracy statement, it is also important to note that manufacturers derive accuracy specs under laboratory conditions using high-emittance, blackbody simulators in a controlled environment. As a result, manufacturers derive accuracy specs under “best case” conditions which may not be possible to duplicate in a given work environment.
To help ensure measurement accuracy, be certain to:
- Always measure perpendicular to target
- Correctly set radiometer inputs for emittance, reflected temperature, distance and humidity
- Ensure target size is adequate for subject radiometer’s spot measurement size
- Temporarily modifying low E targets can help to improve measurement accuracy
Lastly, real-world challenges can create situations where it is not possible to measure temperatures to the accuracy level promised by an instrument’s spec sheet. These challenges include, but are not limited to, hot or cold ambient temperatures, and the use of different lenses or filters. Whenever accurate infrared temperature measurement is not possible, one should consider using contact thermometry instead.
Infrared imager selection and operation are two of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course . For information on our open enrollment or Distance Learning courses, please visit us online at www.infraspection.com or call us at 609-239-4788.
IR Inspections of Photovoltaic Systems
Tip written by: Infraspection Institute
With interest in renewable energy at an all-time high, photovoltaic systems have become a common sight worldwide. Infrared inspections can be used for quality assurance inspections of new installations or to monitor the performance of existing ones.
Photovoltaics is a method of converting solar energy into electricity. A photovoltaic system uses an array of several solar panels each of which is comprised of several solar cells. When exposed to sunlight, the solar cells produce direct current electricity. This DC power can then be converted to AC power for local use or to supply a power grid.
Defective cells or wiring within solar panels can cause hotspots that compromise the power output of the panel. Such hotspots are readily detected with a thermal imager while the panel is exposed to sunlight. Performed from either the topside or underside of panels, infrared inspections provide the most cost effective method for detecting defects within installed panels.
Thermogram courtesy Testo India
When performing an infrared inspection of an installed PV system, keep the following in mind:
- Determine best vantage point for the IR inspection
- Inspections should be performed on a sunny day when winds are calm
- Qualitatively inspect panels looking for inexplicable hot or cold spots
- Be sure to include the electrical conductors and distribution equipment that connect solar panels to the electrical system
Lastly, make certain to observe all safety precautions during the infrared inspection especially when working from an aircraft or an elevated vantage point. Personnel should also take care to avoid electrical hazards when working near exposed, energized electrical conductors.
Infrared inspections of photovoltaic panels 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 Installed Photovoltaic Systems, visit us online at www.infraspection.com or call us at 609-239-4788.
Normal Hot Spots in Electrical Systems
In general, hot spots within electrical systems are indicative of problems such as loose connections or overloaded circuits. For some electrical components, high temperature operation is normal and an infrared imager can be used to help ensure that these devices are functioning.
During a routine infrared inspection of electrical distribution systems, similar components under similar load are compared to each other. Items appearing inexplicably hot are reported as exceptions to be further investigated and appropriately repaired. For components that normally operate at elevated or high temperature, a lack of heat may be indicative of an exception.
Capacitors used for power factor correction are good examples of components that are normally warm. Properly functioning capacitors should operate above ambient temperature and their casings should be uniform in temperature when compared to similar units under similar load.
Thermal overload relays are found in many motor controllers. The elements of these relays, often called heaters, may operate at high temperature when the circuit is under load. When compared to adjacent phases, these elements should be similar in temperature with no pronounced hot spots.
Electric strip heaters are used to control humidity within switchgear enclosures. Switchgear heaters usually operate at very high temperatures and their operation can easily be verified with an infrared imager. Cold strip heaters may be indicative of a failed element, improper control settings, or a de-energized control circuit.
The above are just three examples where elevated temperatures are normal. Thermographers should always be on the lookout for cold spots that may be indicative of problems in addition to hot spots traditionally associated with exceptions.
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.
Determining Acceptable Load for Electrical Circuits
Tip written by: Infraspection Institute
Infrared thermography is a useful tool for detecting heat patterns caused by overloaded electrical circuits. In this Tip we discuss what constitutes an acceptable load.
Infrared imagers are capable of detecting thermal patterns associated with several electrical deficiencies including overloaded circuits. When viewed with an imager, overloaded circuits will appear warm throughout their entire length with no discrete hot spots. Since it is not possible to determine circuit load from a thermal signature, actual circuit load must be measured with an ammeter.
Once circuit load is known, a question that frequently arises is, ‘How much load is acceptable?’ The answer to this question can be found within the National Electric Code 220-10(b) which provides guidance for circuit loading.
- (b) Continuous and Noncontinuous loads. Where a feeder supplies a continuous load or any combination of continuous or noncontinuous loads, the rating of the over-current device shall not be less than the noncontinuous load plus 125 percent of the continuous load. The minimum feeder circuit conductor size, without the application of any adjustment or correction factors, shall have an allowable ampacity equal to or greater than the noncontinuous load plus 125 percent of the continuous load.NOTE: Exception: Where the assembly including the over-current devices protecting the feeder(s) are listed for operation at 100 percent of their rating, neither the ampere rating of the over-current device nor the ampacity of the feeder conductors shall be less than the sum of the continuous load plus the noncontinuous load.
In other words, for most circuits load should not exceed 80% of conductor ampacity or 80% of the overcurrent device rating. To help ensure accuracy, electric loads should be measured with a true RMS sensing ammeter.
Infrared inspection of electrical equipment is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. This same subject is also the focus of our 16 hour application course, Infrared Inspection of Electrical Systems. For more information or to register for a course, visit Infraspection Institute or call us at 609-239-4788.
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RSS News Feeds – An Easy Way to Stay Current
RSS feeds have become a means for automatically receiving information from web publishers on a wide variety of topics. RSS feeds can provide thermographers with up-to-the minute news and information on thermography and related PdM and NDT topics.
One of the definitions of RSS is “Really Simple Syndication”. It is a way to easily distribute a list of headlines, update notices, and sometimes content to a wide number of people. An RSS feed is sometimes called an “RSS Channel.” RSS works by having the website author maintain a list of notifications on his/her website. This list of notifications is called an “RSS Feed.”
Thermographers can benefit from an RSS feed by having the feed automatically deliver content to their computer. This is accomplished via software programs called “News Readers” or “RSS Aggregators.” There are many aggregators available for free as well as some that charge a fee. Every aggregator is different but each one will allow you to create an incoming feed that interests you.
Upon selecting and installing your aggregator, enter the URL of each RSS feed you wish to receive into the appropriate location in your aggregator. By running your aggregator in automatic mode, it will periodically check the internet to see if selected feeds have been updated. If the aggregator finds an update, it will download the updated information to your computer. Then, when you read a headline that interests you, just click on it and you’ll be able to read the full story.
Both infraspection.com and irinfo.org offer free news feeds. To receive feeds from these websites, enter the URLs listed below into your aggregator program.
INFRASPECTION.COM
https://www.infraspection.com/rss_news_feeds/infraspection_news.xml
IRINFO.ORG:
https://irinfo.org/rss_news_feeds/rss_irinfo_main.xml
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Insuring Equipment In Transit
Tip written by: Infraspection Institute
Shipping infrared equipment is a frequent necessity for thermographers. Taking the time to make certain that equipment is adequately insured can help prevent bigger problems in the event of loss or damage.
Many companies insure their infrared equipment to guard against loss or damage while the equipment is in use or transit by company employees. Typically referred to as Inland Marine or Scheduled Equipment, this coverage is generally purchased in addition to the contents portion of a company’s general insurance policy. In order to be covered, equipment must be specifically identified by make, model, serial number and value.
For those who find it necessary to ship equipment via a third party or common carrier, purchasing additional coverage known as ‘Goods in Transit’ may be a smart move. While many shipping companies offer options for ‘insurance’, such coverage is often quite limited and may be insufficient to properly guard against loss. In addition to providing better coverage, a Goods in Transit policy is usually less expensive than insurance offered by freight or parcel carriers.
Regardless of how you insure your equipment, be certain to review your policy with your insurance professional and understand exactly what is covered. Lastly, always make certain that equipment is covered for replacement cost rather than ‘Fair Market Value’.
Care and use of infrared equipment is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer training course. For more information including course locations and dates, visit us online at infraspection.com.
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May 18, 2015
Sponsored by: Keysight Technologies
Four Steps to Solving Problems
Solving problems is a constant challenge for most managers. The effectiveness of a manager is directly tied to their ability to accurately define a problem and find the most effective solution. This week’s Tip discusses a simple and proven method for solving even the toughest problems.
Like any project, problem solving involves a series of steps. When completed, the following simple steps should provide an effective solution to nearly any problem. Be certain to complete the steps in order before advancing to the next step.
Step 1: Define the Problem. This is often the most difficult part of solving any problem. Without an accurate problem definition, we cannot begin to find an appropriate solution. When defining a problem, keep it simple and direct, limiting your description to 10 words or less. Once you are certain that your problem definition is accurate, proceed to Step 2.
Step 2: Outline Possible Solutions. Make a list of all possible solutions to the problem you’ve defined. Feel free to brainstorm and let your imagination run free. This is a step for gathering ideas – not for being critical. When appropriate, be sure to seek the input of others.
Step 3: Determine the Best Solution. Drawing from the list generated in Step 2, select the best possible solution to the problem.
Step 4: Implement Your Best Solution. Be sure to monitor the problem and your implemented solution for its effectiveness. If your chosen solution is ineffective, return to Step 3 for an alternate idea.
Solving problems associated with managing an infrared inspection program is one of the many topics covered in the Level III Infraspection Institute Certified Infrared Thermographer® training course. For more information including course locations and dates, visit us online at Infraspection
May 25, 2015
Sponsored by: Keysight Technologies
When Should You Upgrade Your Imager?
With any technology, change is inevitable. Advances in infrared imager technology now provide thermographers with new equipment choices on a semiannual basis. With more choices than ever, it is important for thermographers to be able to determine when they should upgrade their imager.
With the recent introduction of 640 x 480 pixel imagers, many have suggested that thermographers with older imaging systems will suffer a loss of business to those with newer equipment. While increased resolution may seem desirable, of greater importance is matching infrared equipment to the task at hand. For imaging large objects or imaging at close range, imagers with lesser resolution may be sufficient to the task.
In addition to improved image quality, there are technical and sound business reasons to consider an upgrade. These include, but are not limited to, the following:
- Increased portability, functionality, and/or ease of use
- Improved measurement accuracy
- Better availability of service, parts, and calibration
- New business opportunities afforded by new equipment
- Customer demand for new features and benefits
Depending upon the age of existing equipment, there may be financial advantages to upgrading or acquiring new equipment. Typically, a professional accountant can offer the best advice in this area.
Infrared equipment selection and operation are two of the many topics covered in all Level I Infraspection Institute Certified Infrared Thermographer® training courses. Open enrollment classes are available at several locations each month and through our Distance Learning Program. For information on thermographer training including course locations and dates, visit us online at www.infraspection.com or call us at 609-239-4788.
June 01, 2015
Sponsored by: Keysight Technologies
Insect Safety Tip
For many, it’s that time of year again when nature’s little wonders come out and remind us that we need to be proactive in reducing our exposure to the flying and crawling types of hazards. In this Tip, we offer suggestions for dealing with mosquitoes, ticks, and bees.
Mosquitoes – Nationwide there are more than 60 different kinds of mosquitoes some of which are capable of spreading disease. Mosquito larvae can develop in both tidal and fresh water locations; the key to minimizing their population is to reduce the availability of standing/stagnant water. Treat, remove or drain “water collectors” such as cans, discarded tires, etc. A single discarded tire can produce tens of thousands of mosquitoes over the course of a season! An insect repellant can help protect you from bites.
Ticks – Ticks like to rest on low-lying brush and “catch a ride” on a passersby. Areas prone to tick infestation are wooded areas and low-growing grasslands. The best way to reduce your risk of tick-bites is to avoid infested areas. When venturing into tick prone areas, stay in the center of paths, avoid sitting on the ground, and conduct frequent tick-checks. Dress properly by wearing a long-sleeved shirt and long pants, tucking your shirt into your pants and your pants into your socks. This reduces the skin area exposed to ticks and thwarts their efforts to crawl onto your skin. Again, an insect repellant can help protect you.
Bees – Keep a lookout for nests and the activity associated with them especially when opening cabinets or enclosures where bees might nest. For small nests or individual bees, knock down sprays may be effective. For large nests or colonies, contact a professional to have them removed.
Medical Attention – Be alert for signs of an allergic reaction to insect bites or stings. Non-emergency symptoms vary according to the type of insect and the individual. Most people have localized pain, redness, swelling, or itching. Signs of severe reaction which require immediate medical attention include trouble breathing, wheezing, shortness of breath, weakness, swelling anywhere on the face and a tightening throat. In such cases, seek medical treatment immediately!
Thermographer safety is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information on open enrollment classes or our Distance Learning courses, visit Infraspection Institute online at www.infraspection.com or call us at 609-239-4788.
June 08, 2015
Sponsored by: Keysight Technologies
A Reminder to Cut the Roof
Stuart L. Raney
Level III Certified Infrared Thermographer
It is a typical roof inspection using an infrared imager to locate hidden moisture. The roof is in pretty good shape and no exceptions have been located on the first two sections. Walking across the third roof section, the first exception is spotted. It is a small one, roughly 2’ x 2’, and appears to be half of a 2’ x 4’ Perlite board.
Stepping in the middle of the exception reveals the softness created when board type insulation becomes wet. With a small exception like this, it is tempting to mark it and move on to the next, but first let’s check it with our capacitance meter. Sure enough, the meter pegs the needle, but to make sure we whip out the pin-type moisture meter. Inserted into the center of the area, it also pegs the needle. So now we have a footstep and three advanced pieces of technology that all agree the roof is wet, or do they?
The footstep only tells us the roof was slightly softer in that area. The infrared imager only reports that the radiated energy was slightly higher. The capacitance meter only reports that the electrical impedance of the area is different from the area around it. The pin-type meter only reports that it encountered a different electrical resistance.
In order to confirm the presence of moisture we take a core sample of the roof. What we found was a piece of sheet metal laid below the membrane, apparently to cover the opening left by an old vent pipe that had been removed. The metal changed the radiated energy seen by the imager, the impedance seen by the capacitance meter, the resistance seen by the pin-type meter and small hole in the deck changed the firmness felt by the footstep. All these were good reasons to suspect a wet area but none good enough to verify one, even when all four agreed.
This is an old tip, but one worth revisiting. This exception was actually encountered on a recent inspection and could have been misinterpreted had the roof not been cored to confirm or deny the other results.
Perhaps a good way to understand the importance of core cuts is to realize that the visible evidence of a core is the only method of investigation that determines if a roof is wet or dry. Infrared imagers, nuclear gauges, capacitance meters and even pin-type resistance moisture meters can only be used to narrow down areas of the roof and limit the number of cores that must be taken. So if you are in the business of roof moisture surveys, your primary tool is a core cutter. You just use the fancy equipment to tell you where to do the real work.
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June 15, 2015
Sponsored by: Keysight Technologies
Infrared Inspection of Parallel Feed Conductors
Parallel conductors are a common feature on many electrical circuits. When properly used, an infrared imager can detect evidence of serious problems that might otherwise go undetected.
Insulated conductors play a vital role in electrical systems by carrying current to connected devices. Single phase circuits in receptacle and lighting panels use individual conductors to perform this function. Feeder type conductors however, are typically much larger in size and load carrying ability and quickly reach a point where it becomes impractical to install them using only one conductor per phase. In these cases, parallel conductors are used.
In theory, each parallel conductor should be the same diameter and length for a specified feeder circuit in order that the carried load is shared evenly among the conductors. Properly functioning parallel conductors on the same phase should exhibit equal temperatures with no discrete hotspots.
During a recent inspection at an industrial site, a 25 F degree temperature rise was observed on one of two, 400 amp rated parallel feed conductors that linked an 800 amp 3-phase breaker to the main lugs of a motor control center. An ampere reading showed that the warm conductor was carrying 450 amps while the paired conductor had less than 1 amp.
showing one cable 25 F degrees warmer than its pair.
An infrared inspection at the main lug compartment of the motor control center showed the same thermal relationship as observed at the main breaker and led to the discovery of a deteriorated connection that no longer was capable of carrying load. Under normal inspection protocol at this facility, this motor control center was not scheduled for infrared inspection for another year. If not for our investigation as to the cause of the thermal anomaly at the main breaker, this overload condition would have persisted and potentially caused a catastrophic failure.
at the main lug of the motor control center.
When performing infrared inspections of parallel feed conductors it is important to understand that paired conductors are sharing load and therefore should have identical thermal patterns. Differing thermal patterns between paired conductors should always be investigated as overload conditions may develop on one or more conductors. Conductors operating at cooler temperatures are usually the result of broken conductors, conductors of drastically different resistance, or connections that have failed completely.
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June 22, 2015
Sponsored by: Keysight Technologies
Accuracy and Sensitivity – Part 1
Tip provided by Wayne Swirnow – Infrared Imaging Services, LLC
Objective specifications are frequently used to describe the performance of thermal imaging systems. In this two-part Tip, we explore the significance of two commonly used, but frequently misunderstood terms: Accuracy and Sensitivity.
Infrared cameras along with most other electronic measurement systems have to manage their own sources of measurement error. These error sources include detector electronics, signal-to-noise ratios along the signal path, non-linearity, thermal drifting of components, gain/offset adjustments, and a host of other internal electronic workings in the measurement chain of the camera. Each component adds its contribution to the overall error of the camera as a measurement system.
Because many electronic measurement systems are similar in function, that is to detect and convert real world analog information into digital numbers, they all tend to use the same two specifications called “Sensitivity” and “Accuracy”. These two specifications combined describe the unit’s ability to state how close the converted value will be to the actual value of the input.
The Sensitivity specification for an infrared imager states the smallest amount of detectable change in the level of radiant power the camera can sense and convert into a digital number. Any change in radiant power smaller than this amount will not be recognized by the system. It is usually a very small number, (near LSB level in digital terms) and for infrared cameras it’s commonly stated as a fraction of one degree C. Typical specifications for Sensitivity are in the range of .2°C , .1°C or .06°C at a given temperature such as 30°C.
Because Sensitivity values are calculated using a blackbody simulator under laboratory conditions, they represent a best case scenario. An imager’s sensitivity can be significantly affected when imaging real world targets. Factors which influence sensitivity include, but are not limited to: target temperature, target emittance, and imager measurement range.
In part 2 of this Tip we will discuss the topic of Accuracy.
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June 29, 2015
Sponsored by: Keysight Technologies
Accuracy and Sensitivity – Part 2
Tip provided by Wayne Swirnow – Infrared Imaging Services, LLC
Objective specifications are frequently used to describe the performance of thermal imaging systems. In part two of this Tip, we explore the significance of our second frequently misunderstood term, Accuracy.
For an infrared camera, the Accuracy specification states how close the camera’s measurement of radiant power will be to the actual radiant power emitted from a target. Things would be less confusing if this spec was called “Inaccuracy” or “Allowable Error” because it is really stating how inaccurate the camera is allowed to be.
Taking a closer look at the specification for Accuracy, it is made up of two separate components which are combined to give a complete statement of Accuracy:
The “Minimum” part of the spec is expressed as a window of temperature where what is measured is guaranteed to be no further away from the actual input than this spec. A typical specification is “± 2ºC”. This part of the spec covers the camera’s error or inaccuracy when dealing with lower levels of radiant power or lower temperature targets.
The “Maximum” part of the spec is expressed as a percentage of the measured value where what is measured is guaranteed to be no further away from the actual input than this spec. A typical specification is “± 2%” of reading”. This part of the spec covers the camera’s error or inaccuracy when dealing with higher levels of radiant power or higher temperature targets.
As the measured value gets larger, the relative contribution from error remains the same as a percent of the total measured value, but its absolute value goes up. For example, 2% of 100 is “2”, but the same 2% of 1000 is “20”. As the measured temperature value increases to say 500ºC, then the ±2ºC spec is inadequate to express the camera’s accuracy because 2ºC out of 500ºC would be less than .05% error and that is not what the camera can do.
This is why the percentage of reading ( ± 2% of reading) component of the spec is needed and why for larger measurement values IT now becomes the dominant factor in the Accuracy spec. And just to make sure the entire range of accuracy in the camera is covered regardless of the measurement value, manufacturers add the statement, ”whichever is greater”.
Now that we understand the separate components of an Accuracy specification, here is the total statement of how well you can expect a typical infrared camera to measure the radiant power of an object:
“Accuracy = ± 2ºC or ± 2% of reading, whichever is greater”
If this is unclear, try this:
Imagine a marksman shooting at a target and we want to describe his ability to hit the bull’s eye mark every time, or more appropriately, define how far away from the bull’s eye he is allowed to deviate. Let’s also define how tightly his shots will be grouped. But here is the problem: hitting the bull’s eye and making tight groups are two separate talents our marksman possesses. Although they are related, they do operate independently in this shooter and therefore need to be discussed and defined individually.
For our marksman, we’ll assign some infrared camera specifications to his shooting so we can set expectations as to his anticipated performance.
Sensitivity – ability to group shots together
Specification: 0.1 inch
Expectation – Our marksman can place shots within one tenth of an inch of each other
Accuracy – ability to hit the bull’s eye dead center
Specification: ± 2 inches or ± 2% of the distance from the target whichever is greater
Expectation – Our marksman is allowed to miss the bull’s eye by up to 2 inches; greater inaccuracy is allowed as distance to the target increases.
As you can see in this example, his grouping talents do not help him in hitting the bull’s eye. By specification he is allowed to miss the bull’s eye by up to 2 inches. Regardless of a camera’s fantastic “Sensitivity” spec, it is allowed to miss an accurate temperature measurement by its “Accuracy” spec!
Tip provided by Wayne Swirnow – Infrared Imaging Services, LLC
