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.
Asphalt or Coal Tar – How to Tell the Difference
When performing an infrared inspection of low slope roofing systems, invasive testing is necessary to confirm the composition and condition of roofing system components. As asphalt and coal tar are incompatible materials, it is imperative to use the correct bitumen to ensure the long term integrity of repaired test sites.
Asphalt and coal tar are hydrocarbon materials commonly used for built-up roofing. While both share a common use in roofing, they are very different in their chemical composition. Asphalt is a petroleum distillate and a byproduct of crude oil refining. Coal tar is a bituminous product that is largely insoluble in petroleum distillates.
Odor is one way to differentiate between asphalt and coal tar – tar has a distinctive creosote smell. A more reliable method is to test bitumen solubility in mineral spirits. This simple test can be performed as follows:
- Obtain a small sample (pea size nugget) from the subject roof
- Soak sample in a small amount of mineral spirits in an empty glass container such as a baby food jar
- Stir sample gently for about one minute and note results
If sample dissolves to black liquid – sample is asphalt; if sample remains intact and/or colors mineral spirits to a yellow/green color, sample is coal tar.
Once bitumen type has been determined, one should use appropriate repair materials along with the same bitumen as indicated by the above test. Doing so will help to ensure the long term integrity of repaired test sites.
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.com or call us at 609-239-4788.
Splash Protection for Your IR Imager
Taking your infrared imager into dusty or wet environments can have disastrous consequences for your imager. While it is best to wait for such conditions to subside, you can use a polyethylene sheet or trash bag to temporarily protect your imager and accomplish a qualitative inspection.
Since not all imagers and trash bags are created equal, you can follow the following steps to ensure good results.
- Set up imager looking at a thermally stable target with a high emittance. If using an imaging radiometer, note the apparent temperature of the target.
- Select a clean, unused, polyethylene trash bag with a uniform thickness.
- Open trash bag and place over imager. Use only a single layer of the bag plastic to cover the lens.
- Use a rubber band to keep plastic smooth and wrinkle free over the imager lens.
- Image target in Step 1 again and note image quality and apparent temperature.
- Repeat above steps using different brand bags and thicknesses until you find a bag that gives minimal attenuation of image and apparent temperature.
- After selecting the bag that works, trim to fit imager so as to prevent a tripping hazard. If your imager requires air cooling, leave the bottom of the bag open so the imager can ‘breathe’.
- When finished imaging, remove bag from imager and discard.
While not glamorous, this procedure can allow you to successfully perform a qualitative inspection in an environment that might otherwise harm your imager.
Infrared equipment selection and operation are two of the many topics covered in all Level I Infraspection Institute Certified Infrared Thermographer® training courses. Level I training is 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.
Heat Stress & Hydration
Tip written by: Infraspection Institute
An ounce of prevention is worth a pound of cure. In last week’s Tip, we covered the topic of heat stress, its symptoms, and treatment. This Tip focuses on the importance of hydration as a preventive measure.
What is heat stress?
Heat stress is a physical hazard. It is caused by environmental conditions and results in the breakdown of the human thermal regulating system. If you work or play in hot environments, your body needs a lot more water than you might think.
What is hydration?
Hydration is the process of adding water. Our bodies need water to do many things. In hot environments we need large quantities of water to help keep our bodies cooled to a temperature that allows them to function properly. Heat stress becomes a health and safety concern when the volume of water we need to function drops below the level necessary to maintain homeostasis. We call this low water condition dehydration or under-hydration. The average person is 7% under-hydrated.
How can I avoid being under-hydrated?
Develop the habit of drinking water at routine intervals. One 8 oz. cup every hour on hot days will assure proper hydration.
How will I know if I am properly hydrated?
Check the color of your urine. You are properly hydrated if your urine is clear, copious in volume, and light yellow in color.
What are the benefits of proper hydration?
Staying properly hydrated will help to avoid heat stress and may increase your energy level. For every 1% under-hydration, you lose 5% of your energy potential.
Thermographer safety is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information on class locations or our Distance Learning program, visit www.infraspection.com or call 609-239-4788.
Three Legs are Better Than None
When it comes to providing a stable platform for a thermal imager, it’s hard to beat a tripod. As thermal imagers have gotten smaller and lighter, many thermographers have all but forgotten this once requisite accessory that can help provide better quality data while reducing stress.
For many PdM applications that require still images only, using a thermal imager in a hand held configuration is usually sufficient. However, for applications that require imaging from a fixed vantage point over extended periods of time or where videotaping is desired, a tripod can be an invaluable accessory. When selecting a tripod there are several things you should bear in mind:
1. Be sure to select a tripod capable of carrying the weight of your imager.
2. Tripods should connect directly to the imager via a 1/4” x 20 set screw. Tripods with plastic quick releases should be avoided as they are subject to wear and can cause an imager to suddenly fall.
3. Tripods with sturdy hardware and locking systems are more secure and generally last longer than inexpensive models.
4. Fluid head tripods are preferable since they provide smooth motion for videotaping and are less likely to drop an imager if the head is left unlocked.
When carrying a tripod be sure to maintain a safe distance from energized electrical equipment or moving machinery.
Proper use of infrared imaging equipment and accessories is one of the many topics covered in all Infraspection Institute Level I and Level II training courses. For more information on thermographer training and certification, please visit infraspection.com or call 609-239-4788.
Rules of Construction: Special Conditions of the Subcontract
Otherwise bright men and women sign one-sided contracts, called contracts of adhesion, every day. If you sign a contract of adhesion as a consumer, the law will be on your side if you try to get clear. As a business owner, not so much. This is the kind of problem that comes up over and over. Maybe it’s time for you to experiment with a different approach.
Try this: have special conditions to your subcontract drawn up – a page or so that addresses the things you won’t swallow under any circumstances – and send it back to the prime contractor every time before you sign anything. If you want the edge, use your own preprinted form for this. Present it as your company’s standard form which never changes. Don’t sign any subcontract before the prime contractor signs your special conditions.
Your special conditions – you can call them supplemental conditions if you want – should be designed to operate as the last word on the subcontract documents before any signed change order. Drafted correctly, special conditions may – once signed by all parties – relieve you of some of the unacceptable subcontract terms presented to you by a prime contractor. If you had a lawyer involved every time, your lawyer would sit with you and discuss revising the subcontract terms as presented, and you could send back a marked-up counterproposal or walk away. That would be the best way to approach things. Sending back blanket special conditions for the prime to consider is a distinct second best, but it’s bound to be better than what you’re doing now.
Mid-level employees in a big outfit are likely to run away if you come back at them with a marked-up subcontract, because nobody wants to stick their neck out and depart from the company’s pre-approved form. Neither does anyone feel incentivized or equipped to negotiate all terms of a legal contract. All they want to talk about is scope, time and price. However, if they need you, especially under deadline, a prime contractor’s representatives who would never countersign a messy marked-up version of their own agreement just might accept preprinted “standard form” special conditions.
This Tip of the Week is condensed from the current article on the author’s website, RJILAW.com. It is not intended to constitute legal advice. Always consult a lawyer before signing a legal document.
Bob Incollingo is an attorney in private practice in New Jersey, and a regular speaker at Infraspection Institute’s IR/INFO Conference. He has been widely recognized since before the turn of the century as the world’s leading authority on thermography law, which he contends does not exist.
Detecting Underground Pipe Leaks
Leaks are a common problem with underground piping systems. Under the correct conditions, infrared thermography can help to detect evidence of leaks from buried piping systems that carry hot or cold product.
When a leak develops in a buried piping system, fluid is lost to the surrounding earth. If a leak from a heated or cooled piping system is sufficiently large, a temperature change will occur at the surface of the ground in the vicinity of the pipe leak.
Leaks from buried piping are generally characterized by amorphously shaped thermal anomalies that appear along the pathway of the subject piping system. The ability to detect a pipe leak will be influenced by several interdependent factors including, but not limited to: pipe operating temperature, pipe system construction, burial depth, amount of loss, soil type and moisture content, and ground cover.
Infrared inspections of buried piping systems are best performed late at night with calm wind conditions. Inspections may be performed on foot, from a motor vehicle or from an aircraft. Performing the inspection late at night will eliminate the effects of solar loading and solar reflection.
During the inspection, the thermal imager is maneuvered over the pathway of the pipeline. Well-defined straight lines that correspond to the location of the buried lines generally indicate a healthy piping system. Amorphously shaped thermal anomalies that cannot be explained in terms of piping system construction or features may be indicative of pipe leaks and should be marked and subsequently investigated for cause.
Infrared inspection of underground piping systems is one of the many topics covered in all Infraspection Institute Level I training courses. For class locations and dates or information on our convenient, Distance Learning courses, visit us online at www.infraspection.com or call us at 609-239-4788.
Monochrome or Multi-Color?
Tip written by: Infraspection Institute
With most thermal imagers capable of displaying images in monochrome or multicolor, many new thermographers ask which color palette is the best choice for effective imaging. The answer will depend on a number of factors including application, delta T associated with the exception, and personal preference.
Because it is usually less confusing than multicolor palettes, grayscale may be better suited for some applications. Additionally, applications that have a large delta T associated with exceptions or where target recognition is important may be better suited for grayscale imaging. Such applications include electrical distribution systems, building envelopes inspected from the interior of the structure, and low slope roof inspections.
Multicolor palettes offer an advantage when imaging targets having a small delta T associated with exceptions or when imaging targets with several discrete temperature zones. Typical applications include mechanical systems, refractory systems, building envelopes inspected from the exterior, and medical/veterinary applications.
For hardcopy reports, printing monochrome images can result in lower cost than multicolor reports. Lastly, the choice to use monochrome or multicolor is largely a matter of personal preference. Thermographers should always use a palette which best represents the observed thermal patterns and provides data that are easily understood.
Infrared camera operation 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 or our convenient Distance Learning Program, visit us online at www.infraspection.com or call us at 609-239-4788.
Tip written by: Infraspection Institute
The month of September is a month of transition for many Americans. With this Tip, we cover the transitional holiday known as Labor Day.
Generally recognized as the end of the summer travel season, early September marks the beginning of NFL and college football seasons, the start of the school year, and for some, the last opportunity to sport white clothing. Most of these traditions are centered around the final major holiday of summer, Labor Day.
With its origins dating back to the 19th century, Labor Day is a celebration of the American labor movement and is dedicated to the social and economic achievements of workers. It constitutes a yearly national tribute to the contributions workers have made to the strength, prosperity, and well-being of their country.
Once celebrated with parades and speeches, Labor Day is now observed with picnics and family gatherings as many Americans take advantage of a long weekend. Wherever your travels take you this holiday, take a moment to reflect upon the contributions made by workers that have helped to shape our country and continue to keep it strong.
School’s Open – Drive Carefully
Tip Provided by American Automobile Association
By early September, over 55 million children across the United States will head back to school. With 13 percent of those children typically walking or biking to their classes, drivers should be especially vigilant for pedestrians before and after school hours. The afternoon hours are particularly dangerous – over the last decade, nearly one in four child pedestrian fatalities occurred between 3 p.m. and 7 p.m.
Launched in 1946, the American Automobile Association’s School’s Open – Drive Carefully awareness campaign was created as a way to help reduce child pedestrian fatalities and injuries. Here are several recommendations from AAA regarding ways drivers can help to keep kids safe:
- Slow down – Speed limits in school zones are reduced for a reason. A pedestrian struck by a vehicle traveling at 25 mph is nearly two-thirds less likely to be killed compared to a pedestrian struck by a vehicle traveling just 10 mph faster.
- Come to a complete stop – Research shows that more than one-third of drivers roll through stop signs in school zones or neighborhoods. Always come to a complete stop, checking carefully for children on sidewalks and in crosswalks before proceeding.
- Eliminate distractions – Research shows that taking your eyes off the road for just two seconds doubles your chances of crashing. Children can be quick, crossing the road unexpectedly or emerging suddenly between two parked cars. Reduce risk by not using your cell phone or eating while driving.
- Watch for bicycles – Children on bikes are often inexperienced, unsteady, and unpredictable. Slow down and allow at least three feet of passing distance between your vehicle and a bicyclist.
Lastly, always maintain a safe distance from a stopped school bus. Be on the lookout for children boarding or exiting school buses.
Using an Isotherm to Detect Potential Condensation Sites
Tip written by: Infraspection Institute
Condensation on interior building surfaces can lead to a variety of problems including conditions conducive to mold growth. Used properly, the isotherm feature found on many infrared imagers can be utilized to spot potential condensation sites.
Simply put, dew point is the temperature at which water vapor in the air will cause condensation to form on a surface. When interior building components are cooled to dew point temperature or lower, water vapor will precipitate out of the air causing water to form on the subject component.
For building envelopes, chronic condensation on interior drywall surfaces can cause unsightly staining by trapping dust or smoke particulates in these areas. Chronic condensation on organic building components is also conducive to mold growth. Condensation often goes unnoticed until building occupants notice stains associated with the aforementioned conditions. Fortunately, a thermal imager can be used to detect condensation problems before they become serious.
To utilize a thermal imager to detect potential condensation sites, identify the dew point temperature for the room or areas that you are inspecting. Set your imager’s isotherm function to appear at, and for several degrees below, the dew point temperature. As you inspect high emittance building surfaces from the interior of the building, note any components that cause the isotherm to appear. These areas should then be further investigated for cause and appropriate action taken.
When using an isotherm, be sure to practice proper measurement techniques giving particular consideration to viewing angle, spot measurement size and emissivity settings.
Infrared inspections of building envelopes is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online or call us at 609-239-4788.
Autumn IR Inspections to Assess Roof Condition
Tip written by: Infraspection Institute
With parts of the US experiencing record setting heat, it is hard to think about winter. For many, autumn provides a perfect opportunity to conduct infrared inspections of flat roofs to help ensure that they are ready for the upcoming colder months.
Summer can be especially tough on roofing systems. High temperatures, building movement, and UV radiation often cause cracks and splits in the waterproofing system. Left undetected, these cracks and splits can lead to roof leaks and premature roof failure. Performing an infrared roof inspection prior to the onset of colder weather can detect evidence of problems and help to direct repair efforts.
Performed under the proper conditions with the right equipment, an infrared inspection can detect evidence of latent moisture within the roofing system often before leaks become evident in the building. For many locations, autumn provides perfect conditions for conducting an infrared inspection and performing any necessary roof repairs.
The best candidates for infrared inspection are flat or low slope roofs where the insulation is located between the roof deck and the membrane and is in direct contact with the underside of the membrane. Applicable constructions are roofs with either smooth or gravel-surfaced, built-up or single-ply membranes. If gravel is present, it should be less than ½” in diameter and less than 1” thick.
For smooth-surfaced roofs, a short wave (2-5.6 µ) imager will provide more accurate results especially if the roof is painted with a reflective coating. All infrared data should be verified by a qualified roofing professional via core sampling or invasive moisture meter readings.
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.