2013
January 07, 2013
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How Delta T’s Understate Priorities
Tip written by: Infraspection Institute
For years, thermographers have traditionally reported apparent Delta T measurements when documenting their findings. Using a default emittance value between .8 and 1.0, apparent temperature measurements are recorded regardless of actual target emittance. While this methodology is fast and easy, it can lead to significantly understated Delta T repair priorities.
The temperature displayed by a radiometer is largely dependent upon the emittance and reflected temperature values entered into the radiometers computer. Typically, errors in either of these settings will cause temperature measurement errors that are exponential in nature and can cause large errors in reporting Delta T’s.
Example: Using an emittance value of 1.0 a thermographer measures the apparent Delta T between two, uninsulated electrical bus bars to be 44ºC. How much can observed temperature vary due to emittance values?
From the above, the following observations can be made:
- Emittance can have a significant impact on Delta T measurements
- The greater the variation between an object’s true emittance and radiometer settings, the more understated the Delta T
- Repair priorities may be significantly understated if accurate emittance values are not utilized
As there is no way to correct for errors introduced by apparent Delta T measurements, thermographers should utilize correct emittance values whenever possible. As always, all thermal anomalies detected during an infrared inspection should be investigated and proper corrective measures undertaken as soon as possible.
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January 14, 2013
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Thermal Imagery to Detect Roof Fasteners
Tip written by: Infraspection Institute
Thermal imaging is a proven technique for detecting latent moisture within low-slope roofing systems. Under the right conditions, thermal imaging may also indicate the number and location of roof fasteners.
Mechanical fasteners are a critical component in flat roofs. Essentially large sheet metal screws that are installed through large steel or plastic plates, mechanical fasteners secure sheets of insulation to the roof deck. In order to help ensure roof system performance, it is critical that each insulation board is installed with a sufficient number of fasteners.
An insufficient number of roof fasteners may be the result of improper design or a contractor attempting to cut corners on material. When fastener quantity is in doubt, a thermal imager may be used to indicate the number and location of fasteners. Typically, fasteners and plates will show as relatively warm components against a cooler background when imaged post-sunset after a sunny day. In the image below, subsurface fasteners and steel plates show as regularly-spaced warm circles.
When attempting to detect thermal patterns associated with mechanical fasteners, keep the following in mind:
- Thermal imaging should begin at or shortly after sunset
- Imagery associated with fasteners may only appear for a short time
- Fasteners may not be detectable on low emittance or gravel-surfaced roofs
Infrared inspections of flat roofs are one of the many applications covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For course schedules or to obtain a copy of the Standard for Infrared Inspection of Insulated Roofs, visit Infraspection Institute online or call us at 609-239-4788.
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January 21, 2013
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Frequency of Infrared Inspections of Electrical Equipment
Tip written by: Infraspection Institute
“How often should electrical systems be thermographically inspected?” Historically, accepted industry practice has recommended that infrared inspections be performed annually; however, site specific conditions may dictate considerably shorter intervals for some equipment or facilities.
According to the 2010 Edition of NFPA 70B Recommended Practice for Electrical Equipment Maintenance, “Routine infrared inspections of energized electrical systems should be performed annually prior to shutdown. More frequent inspections, for example, quarterly or semiannually, should be performed where warranted by loss experience, installation of new electrical equipment, or changes in environmental, operational, or load conditions.”
Semi-annual infrared inspections may also be prudent where unscheduled outages of electrical equipment could pose significant environmental or safety hazards, or result in catastrophic damage to other systems or components.
Because infrared inspections are only effective when electrical system components are energized, it is imperative to perform infrared inspections when subject equipment is operational. For facilities with seasonal equipment such as heating and cooling systems, it may be necessary to schedule infrared inspections on several different days spread throughout the calendar year.
As always, infrared inspections of electrical systems should only be performed by properly trained and certified thermographers following all appropriate safety precautions. For information on thermographer training and certification or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems and Rotating Equipment, contact Infraspection Institute at 609-239-4788 or visit us online at: www.infraspection.com.
To obtain a copy of NFPA 70B, contact the National Fire Protection Association at 1-800-344-3555 or visit them online at: www.nfpa.org.
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January 28, 2013
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Spare Parts to the Rescue
Tip written by: Infraspection Institute
Seasoned professionals know the value of spare parts when it comes to facility maintenance. The principle of always being prepared can be successfully applied to an infrared inspection program as well.
Like any electrical or mechanical device, thermal imaging systems are subject to wear and tear. Having user-replaceable spare parts on hand can help prevent unscheduled downtime for your infrared inspection program. Building a spare parts inventory is easy if you follow a few simple steps:
1. Examine your equipment for parts that are subject to physical wear such as eyepieces, switch covers or hand/neck straps.
2. Identify which parts are fragile and are most likely to break such as viewfinders or external monitors.
3. Determine which items are critical to operation such as power/video cables, batteries, fuses, screws and external hardware.
4. Inventory items which are easily misplaced such as lens caps and flash cards.
5. Purchase necessary items as soon as possible to ensure availability of specialty or custom parts. For critical items, be sure to purchase extras.
6. Replace spare parts when utilized to maintain inventory.
After building your spare parts inventory, keep mission-critical components in a safe place or with your imager so that you will have them when needed.
Infrared imager operation and maintenance are two of the many applications covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information or to register for a course visit us online at www.infraspection.com or call us at 609-239-4788.
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February 04, 2013
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Preventing Workplace Falls
Tip written by: Infraspection Institute
“Watch Your Step”. Sage advice that we’ve heard a million times; however, falls continue to be one of the most common workplace accidents. Following a few simple steps can help thermographers to prevent most falls.
Each year falls in the workplace account for over one million injuries and several hundred fatalities. Even a simple slip can cause serious injuries. Many falls can be prevented by following some basic rules:
- Identify all potential tripping and fall hazards before work starts
- Look for fall hazards such as unprotected floor openings/edges, shafts, skylights, stairwells, and roof openings/edges
- Use appropriate fall protection equipment; inspect equipment for defects prior to each use
- Never use boxes or chairs in place of an appropriate ladder or stepstool
- Secure and stabilize ladders before climbing them; never stand on top rung or step of a ladder
- Use handrails when going up/down stairs
- Practice good housekeeping – Keep floors dry and free of clutter such as cords, hoses , and cables
- Keep walkways free of snow and ice
Lastly, be sure to use sturdy footwear appropriate to the task. Work boots and shoes should be laced and tied to prevent tripping and to afford proper support. When it comes to fall protection, an ounce of prevention is worth a pound of cure. For more information on workplace safety standards and fall protection, visit www.osha.gov.
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February 11, 2013
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IR Inspections and Mold Safety
Tip written by: Infraspection Institute
The past few years have seen a marked increase in the use of thermography to help detect the presence of mold. When working near mold, thermographers should be aware of the health risks associated with it and take appropriate safety precautions.
Molds are microscopic organisms found everywhere in the environment, indoors and outdoors. When present in large quantities, molds have the potential to cause adverse health effects. Such effects include: sneezing, cough and congestion, runny nose, aggravation of asthma, eye irritation and skin rash. People at greatest risk of adverse health effects are individuals with allergies, asthma, sinusitis, or other lung diseases and those with a weakened immune system.
Mold growth is common on organic building materials that have been wet for sufficient periods of time. Wetting can be the result of structural leaks, high relative humidity, or flooding. When present, mold can appear as discolored areas, woolly mats or a slimy film. Mold is often accompanied by a foul, musty, or earthy smell.
When working near mold, thermographers should keep the following in mind:
- Hand, eye and respiratory protection should always be worn
- Care should be taken not to disturb suspect mold areas
- Tools or clothing that contact mold should be isolated and properly sanitized to avoid contamination of clean areas
- Persons accidentally contacting contaminated areas should immediately wash with soap and water
Lastly, mold can only be positively identified through proper laboratory analysis. Whenever mold presence is suspected, verification testing should be performed by a qualified mold professional.
Detecting latent moisture within structures 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 information on mold or to locate a qualified mold professional, visit the National Organization of Remediators and Mold Inspectors.
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February 18, 2013
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How to Calculate Transmittance
Tip written by: Infraspection Institute
Windows are semi-transparent materials placed between an object and an infrared instrument to separate conditioned from unconditioned spaces. When measuring temperatures through a window, it is imperative to know and enter the Transmittance value of the window into your radiometer’s computer to help ensure temperature measurement accuracy.
Because no object is 100% transmissive, infrared windows will always have Transmittance values of less than 1.0. Following the procedure listed below, it is possible to calculate the T value of any window.
Equipment Required:
- Calibrated imaging radiometer with a computer that allows user to input Reflected Temperature and Emittance values.
- Blackbody simulator with E ≥ 0.95 heated close to temperature of target to be measured.
- Window that is semitransparent in the waveband of the imaging radiometer.
Method:
- Place imaging radiometer at desired distance from blackbody simulator.
- Aim and focus imager on blackbody simulator. Place crosshair on center of blackbody simulator.
- Set imager’s E control to 1.0
- Measure and compensate for Reflected Temperature.
- Measure and note apparent temperature of blackbody simulator.
- Place window directly in front of imaging radiometer’s lens.
- Without moving imager, adjust E control until observed temperature matches value obtained in Step 5 above. The displayed E value is the Transmittance percentage for this window with the subject imaging radiometer. For greater accuracy, repeat above steps a minimum of three times and average results.
The above procedure is described in detail in the Standard for Measuring and Compensating for Transmittance of an Attenuating Medium Using Infrared Imaging Radiometers available from Infraspection Institute. For more information or to place an order, call 609-239-4788 or visit us the Infraspection Online Store.
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February 25, 2013
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How Dust Creates Full Size Thermal Imagery
Tip written by: Infraspection Institute
When performing an infrared inspection of the interior of a building, you may be able to visually observe full-size thermal images without your thermal imager. The cause of this phenomenon is simple dust and dirt normally found within most buildings.
Many buildings employ cavity wall details in the construction of interior spaces. When the exterior of framed walls are exposed to cold temperatures, areas with diminished R values will cause the interior surfaces of the wall to cool. Such cold areas may be caused by framing members or wall cavities with missing or damaged insulation.
If interior humidity levels are high and outdoor temperatures sufficiently low, moisture will condense on the wall surfaces within the occupied spaces. Once moisture condenses on the wall surfaces, dust and smoke particles can collect in these areas and will remain once the wall surface has dried.
Thermal patterns caused by dust and condensation are readily observed for light-colored walls with smooth surfaces such as drywall coated with smooth latex paint. The intensity of the resulting dust patterns will be dependent upon humidity levels, wall temperatures, and the amount of particulates within the air.
Typically dust patterns are more intense within areas occupied by smokers, within kitchens, near woodstoves or fireplaces, or in areas where candles are burned. Over time, dust patterns can become quite pronounced and will often clearly show every framing member and insulation deficiency within the wall.
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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Choosing and Maintaining Your Domain Name
Tip written by: Infraspection Institute
“What’s in a name? That which we call a rose by any other word would smell as sweet.” This Shakespeare quote implies that names are not that important; however, Sir William never had a website. In this Tip we discuss the importance of website domain names.
When setting up a website, choosing a domain name is one of the most important considerations. A domain name not only represents your online identity, it can seriously influence the success of marketing a company and its products and services. Prior to selecting a domain name, it is important to understand the short and long-term implications of domain name choice.
A general rule of thumb for domain names is www.yourcompanyname.com. This convention works well if your company name is recognized and/or unique. This can get tricky if your company name is long or contains characters such as hyphens. Domain names can only use letters, numbers, or dashes; spaces and symbols are not allowed.
When selecting a domain name, keep the following in mind:
- Keep it short. Although domain names can be up to 63 characters in length, shorter names are easier to remember
- Avoid trademarked names. Cybersquatting is illegal and not well tolerated by trademark owners
- Register selected domain name(s) immediately. Include all appropriate extensions: .com, .net., .org, .biz
Lastly, be certain to renew domain name registrations on time to avoid loosing your ownership. Expired domain names that are not trademarked can be purchased by a third party and used to point traffic to websites of their choice.
Designing and maintaining an effective website is one of the many topics covered in the Infraspection Institute Level III Best Practices training course. For more information on thermographer training and certification or to register for a course, visit us online at www.infraspection.com or call us at 609-239-4788.
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Do You Have the Correct Time?
Tip written by: Infraspection Institute
Most modern thermal imagers have the ability to record time and date along with thermal images. Taking a moment to ensure that the correct time and date are displayed on your imager before you begin your inspection can help to avoid wasted time and the collection of inaccurate data.
Having the correct time associated with your imagery is important for several reasons. With correctly dated imagery, it is possible to:
- Accurately document when the inspection was performed
- Easily store and uniquely reference image files
- Record the duration of a thermal event
It is always good practice to consciously check your imager’s clock each time you start your imager and make any necessary adjustments. Be certain to check your clock periodically during your inspection and whenever you restart your imager such as after a battery change or power interruption.
If your imager frequently displays incorrect time, it may be indicative of a defective or dead internal battery. To help avoid this problem, arrange for replacement of internal clock batteries whenever you have your imager serviced or repaired.
Infrared imager operation and use 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 us online at www.infraspection.com or call us at 609-239-4788.
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Building Envelope Inspections – Which Way Do We Go?
Tip written by: Infraspection Institute
Infrared inspections of building envelopes have many uses. Of paramount importance is a logical inspection route that covers all subject areas and provides report data that can be easily followed.
Infrared inspections of building envelopes may be performed to detect evidence of thermal deficiencies and/or latent moisture. Typically, infrared inspections cover the exterior walls, windows, doors, and ceilings or roof of the structure. Depending upon the reason for the inspection, the inspection may be performed from either an interior or exterior vantage point. Regardless of vantage point, complete coverage all subject surfaces is critical to inspection success.
One method of helping to ensure complete coverage is to begin the inspection at a recognizable reference point such as a main doorway or other easily identified feature. From this starting point, the inspection is conducted for all subject surfaces of the building while moving in a clockwise fashion.
Moving in a clockwise fashion allows a thermographer to move in a logical and predetermined fashion around the building. This practice will work equally well when working from either the interior or exterior of the building. When thermal imagery is recorded to videotape, clockwise routes can help a viewer to better understand recorded data when viewing the tape at a later time.
The topic of infrared inspections of building envelopes is 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 Inspection of Building Envelopes,contact Infraspection Institute at 609-239-4788 or visit us online at www.infraspection.com.
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Spring is the Time for Infrared Roof Inspections
Tip written by: Infraspection Institute
With onset of warmer weather, the harshness of winter is but a fading memory for most. Left undetected, the damage caused by winter’s fury is a reality that can lead to premature roof failure. Fortunately, an infrared inspection of your roof can detect evidence of problems before they can get out of hand.
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.
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 obtain a copy of the Standard for Infrared Inspection of Insulated Roofs, visit Infraspection Institute or call us at 609-239-4788.
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Understanding Emissivity
Tip written by: Infraspection Institute
Emissivity refers to an object’s ability to radiate infrared energy. Because infrared instruments measure radiant energy, it is imperative for a thermographer to understand emissivity and how it can vary.
All objects above 0 Kelvin radiate infrared energy. The amount of energy radiated is dependent upon an object’s temperature and emittance. Increases in temperature and/or emittance will increase the amount of infrared energy radiated.
Although many equate emissivity to values published in emittance tables, emissivity is a dynamic characteristic and is influenced by several factors. Among these are:
Wavelength – For most objects, emissivity varies with wavelength.
Object Temperature – Changes in object temperature cause changes in Emissivity
For clean metals, E increases with temperature rise
For dielectrics, E decreases with temperature rise
Viewing Angle – Imaging at angles other than perpendicular causes changes in Emissivity
Target Geometry – Target shape affects Emissivity. Compared to a flat surface,
Concave shape increases E
Convex shape decreases E
Surface Condition – Surface roughness, texture, or condition (dirt, oxidation or paint) can significantly affect Emissivity
Although thermographers frequently obtain emittance values from published tables, this practice can introduce significant temperature measurement errors since emittance tables cannot account for several of the above factors. Because of this, calculating emittance with one’s thermal imager will help to ensure measurement accuracy.
The topic of emissivity is covered in all Infraspection Institute Level II Certified Infrared Thermographer® training courses. For more information on thermographer training, including class locations and dates, call us at 609-239-4788 or visit us online at www.infraspection.com.
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How to Deal With Emittance
Tip written by: Infraspection Institute
The perpetual question among those using radiometric equipment is, “What emittance value should I use?” In this Tip, we address several options for providing emittance values.
Emittance is a numerical value between 0 and 1.0 indicating an object’s relative ability to radiate infrared energy. Most radiometers allow the user to input emittance values into the radiometer’s computer. Utilizing correct emittance values is imperative for accurate non-contact temperature measurements.
When determining emittance values for a target, there are five accepted ways to obtain an emittance value. These methods are listed below in order of increasing complexity and accuracy.
- Use General Default Values – Organics are generally > 0.80.Metals can vary widely from < 0.1 to > 0.90
- Use Emittance Tables – Be certain to use tables that match your radiometers spectral response and your target’s temperature.
- Estimate Emittance -Choose representative sample and test for emittance value. Use these values whenever similar object is encountered in the future.
- Modify Surface to a Known Emittance Value. Use tape, paint, or powder with known E. Prior to modifying any surface, be certain it is safe to do so.
- Measure Emittance Value – Use subject radiometer to measure target E value. This practice is preferred as it provides the most accurate emittance values.
The procedure for measuring emittance values is described in detail in the Standard for Measuring and Compensating for Emittance Using Infrared Imaging Radiometers available from Infraspection Institute. For more information on infrared standards or thermographer training, call 609-239-4788 or visit us online at www.infraspection.com.
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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.
Understanding the impact of environmental conditions on infrared inspections is one of the many topics covered in the Infraspection Institute Level I Certified Infrared Thermographer® training course. For more information including course locations and dates, visit Infraspection Institute online or call us at 609-239-4788.
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IR Inspections of Furnace Tubes
Tip written by: Infraspection Institute
Process furnaces or heaters are a critical component found in many petrochemical refineries. Performed properly, infrared inspections of furnace tubes can provide valuable data regarding tube condition and operating temperature.
Process heaters are large, refractory-lined structures used to heat hydrocarbon product during refining. Process heaters are similar to steam boilers in their construction except that hydrocarbon is passed through the firebox tubes instead of water. Safe operation of process heaters requires that tubes operate below their maximum operating temperature. Overheating of tubes can reduce operational life or lead to catastrophic failure.
Measuring tube temperatures is difficult for many reasons. Tubes are often remotely located from inspection ports and are frequently obscured by visually opaque flames. High temperature environments make contact measurements difficult or impossible. Under the right circumstances, infrared thermography can be used to provide qualitative and quantitative data for in-service heater tubes. The following images were taken through viewports on operating heaters.
Image taken through opaque flame.
Image taken through opaque flame.
Infrared inspection of process furnaces or heaters is one of the most difficult tasks for thermal imaging and infrared radiometry. Accuracy in temperature measurement is of paramount importance since many companies utilize infrared data to determine safe operating limits for in-service heaters.
Far from being a “point and shoot” application, a thermographer needs to understand heater operation and heat transfer as well as issues pertinent to thermography. These include, but are not limited to: infrared camera selection including proper spectral response and spot measurement size; imager calibration; use of filters, windows and heat shields; calculating emittance and reflected temperature; equipment precision and accuracy; and how to obtain reliable reference temperatures to verify proper imager settings.
To help ensure accuracy, thermographers should be trained to at least Level II and, when possible, work with an experienced mentor until they have gained sufficient field experience.
Infrared inspection of process heater tubes is one of the applications covered in the Infraspection Institute Level II Certified Infrared Thermographer® training courses. For more information or course schedules, visit us online at www.infraspection.com or call us at 609-239-4788.
More information on this subject is available a free download from this website by visiting: Applications of Infrared Thermography for Petrochemical Process Heaters.
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Offering Infrared Inspection Services
Tip written by: Infraspection Institute
The ever-increasing awareness of thermography causes many to consider offering infrared inspection services through new or existing business ventures. In general, the time has never been better than the present for starting an infrared consulting business or adding infrared inspection services to an existing company’s services.
The advent of lower cost technology has increased the number of commercial thermal imagers being offered while reducing the cost for same. This, combined with a greater awareness of the technology, has served to increase the demand for infrared inspection services.
During the past two years, the lower cost for infrared imagers and software has been an inducement for many large companies to purchase equipment; it has also attracted a number of entrepreneurs to the industry as well. Despite the fact that infrared equipment has become cheaper and the number of infrared consultants has increased, there remains a shortage of experienced, competent thermographers. From all market indications, this shortage of quality thermographers should provide favorable business opportunities for the next several years.
Prior to offering infrared inspection services, one should consider the following for your intended market area:
- Current demand for infrared inspection services
- Present competitive offerings and pricing
- Company’s strengths and current services
- Types of infrared inspections to be offered
- How new services will be marketed
Lastly, once a decision has been made to offer infrared inspection services, thermographers should obtain quality training and certification before they purchase infrared inspection equipment. For more information on training or certification services, contact Infraspection Institute at 609-239-4788.
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A Thermographer’s Magic Marker
Tip suggested by: Randall D. Cain, American Water Company
An age-old challenge for thermographers is the ability to annotate or mark objects to make them easier to identify in recorded imagery. One possible solution is to mark targets with an ink pen with low emittance ink.
Many thermographers have long sought ways to mark targets in such a fashion that numbers or text can clearly be seen with a thermal imager. Over time, some thermographers have used paints with emittances that contrast sharply with the objects being marked. In these cases, text and/or numbers painted on the target are clearly visible within resulting thermal imagery and recorded thermograms.
Recently some thermographers have reported good results in utilizing a Sharpie permanent felt-tip marker in silver color. The low emittance of the metallic ink contrasts markedly with high emittance targets allowing annotations to clearly appear within thermal images. In many cases, the silver ink can also be clearly seen in daylight images as well. An example can be seen below.
One should be aware that Sharpie markers are permanent unless the ink is applied to a removable material such as tape or labels affixed to the target. Prior to marking any target, be certain it is safe to do so and that marking will not permanently damage the target.
For more information on thermographer training and certification or to obtain a copy of the Standard for Infrared Inspection of Electrical Systems and Rotating Equipment, call Infraspection Institute at 609-239-4788 or visit us online at wwww.infraspection.com.
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Warm Lighting Circuit Breakers
Tip written by: Infraspection Institute
When performing infrared inspections of branch circuit panels, lighting circuits will often appear warmer than adjacent circuits. If adjacent circuits are lightly loaded, the warmer circuits may be indicative of a normal condition or they may represent a more serious condition.
For electrical panels with single-phase branch circuits, is often quite normal for lighting circuit circuits to appear warmer as they frequently have some of the highest loads within the panel. To confirm this, load readings should be obtained with a true RMS ammeter to determine that the subject breakers are operating within specifications. For long term use, it is recommended that circuits operate at less than 80% of their rated capacity.
If lighting circuit breakers are used as switching devices, they must be rated as Switch Duty. Using non-switch-rated breakers can cause excess wear on the breaker contacts. To determine the integrity of breaker contacts, one should remove the breaker from service and perform a contact resistance test through the breaker with the breaker in the closed position. Such testing should be performed with a digital low resistance ohmmeter.
If lighting circuits have fluorescent fixtures or other solid state devices connected to them, the circuits are likely to contain significant harmonic content. To determine if significant harmonics are present, the subject circuit should be tested with a harmonics analyzer.
In lieu of testing a suspect breaker, you may wish to replace it with a new one and re-image the subject circuit to ascertain if the situation has improved.
Infrared inspections of power distribution systems is one of the many topics covered in the Level I Infraspection Institute Certified Infrared Thermographer® training course. For information on thermographer training including course locations and dates, visit us online at www.infraspection.com or call us at 609-239-4788.
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The Best Recommendation
Tip written by: Infraspection Institute
As part of their infrared inspection reports, thermographers frequently include exception diagnoses along with recommendations for repair. In this Tip, we offer our suggestion for the only recommendation a thermographer will ever need.
When used as a tool for Preventive/Predictive Maintenance, thermography can detect and document evidence of thermal patterns and temperatures across the surface of an object. The presence of inexplicable thermal anomalies is often indicative of incipient failures within inspected systems and structures. Because thermography alone cannot determine the cause of an exception, other diagnostic tools must be employed to determine the cause of observed exceptions.
Although thermography is inconclusive, thermographers frequently provide opinions as to the cause of exceptions without having the benefit of confirming test information. Such opinions are frequently accompanied by elaborate recommendations for repair. When such observations/recommendations are incorrect, they can cause repair efforts to be misdirected.
Unless a thermographer has performed, or has access to, confirming tests, providing opinions regarding the cause of exceptions and subsequent recommendations for repair is unwise. When confirming test data are unavailable, a prudent thermographer should make only one simple recommendation: “Investigate and perform appropriate repair”.
Generating standards-compliant reports 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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Tornado Safety
Tip written by: Infraspection Institute
With the onset of warm weather, tornado season has arrived. In an average year, tornadoes in the US cause 80 fatalities and 1500 injuries. Knowing what to do before and during a tornado is crucial for survival.
Tornadoes are nature’s most violent storms. Spawned from powerful thunderstorms, tornadoes can cause fatalities and devastate a neighborhood in seconds. A tornado appears as a rotating, funnel-shaped cloud that extends from a thunderstorm to the ground with whirling winds that can reach 300 miles per hour. Damage paths can be in excess of one mile wide and 50 miles long. Every state is at some risk from this hazard.
Some tornadoes are clearly visible, while rain or nearby low-hanging clouds obscure others. Occasionally, tornadoes develop so rapidly that little, if any, advance warning is possible. The best defense against tornadoes is to be alert to weather conditions and be ready to seek shelter.
Before a tornado, be alert to changing weather conditions.
- Listen to NOAA Weather Radio or to local newscasts for the latest information
- Watch for approaching storms
- Know the danger signs:Dark, often greenish sky, Large hail, Large, dark, low-lying or rotating clouds,Loud roar, similar to a freight train
If you see an approaching tornado or are under a tornado WARNING, seek shelter immediately.
- If you are in a structure, go to a pre-designated shelter area or the center of an interior room on the lowest building level. Get under a sturdy table and use your arms to protect your head and neck. Do not open windows.
- If you are in a vehicle, get out immediately and go to the lowest floor of a sturdy, nearby building or a storm shelter. Mobile homes, even if tied down, offer little protection from tornadoes.
- If you are outside with no shelter, lie flat in a nearby ditch or depression and cover your head with your hands. Beware of flying debris and the potential for flooding.
For more information on tornadoes and tornado safety, visit the NOAA website.
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Improving Accuracy of IR Temperature Measurements
Tip written by: Infraspection Institute
As infrared technology has advanced, radiometers have become a common tool for many maintenance technicians and mechanics. Although radiometers are relatively easy to use, there are several important factors that influence the accuracy of a radiometer’s readings. Infrared radiometers offer several advantages when it comes to temperature measurements.
Measurements are non-contact, non-destructive and can be obtained quickly. Unfortunately, radiometers are not self-diagnostic and cannot warn the operator of erroneous readings. The following are some simple tips that can help to ensure accurate infrared temperature measurements.
- Target should be stationary and at a stable temperature with a dry surface
- Radiometer lens should be clean and free from obstructions
- Radiometer batteries should be fully charged
- IR temperature measurements should be made perpendicular to target
- IR radiometer should be operated at a distance to ensure that spot measurement size is smaller than the target
- Accurate emissivity and reflected temperature values should be input into the radiometer’s computer.
Whenever possible, infrared readings should be correlated with known temperature values. If a discrepancy is observed, it could be due to a procedural error in measurement or the radiometer may require calibration.
For more information on infrared temperature measurement, or to obtain information on thermographer training and certification, contact Infraspection Institute at 609-239-4788 or visit us online at www.infraspection.com.
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Temperature Rise as a Severity Indicator
Tip written by: Infraspection Institute
For years, many thermographers have sought to qualify the severity of detected exceptions by measuring temperature rise. Although this technique is widely practiced, failure to understand key issues can lead to misdiagnoses and unplanned downtime.
For over 25 years, thermographers have frequently attempted to qualify the severity of detected exceptions by comparing the temperature of the exception to similar components under similar load or to ambient air temperature. Although qualifying exception severity may be desirable for maintenance planning, it also involves a certain degree of risk management as some exceptions may rapidly deteriorate and lead to an unplanned outage.
To better understand the risks associated with assigning severity to exceptions based upon temperature, it is important to keep the following in mind:
- For highly reflective targets, small emissivity errors can cause significant infrared temperature measurement errors
- Infrared temperatures are subject to errors due to spot measurement size
- The source of an exception may be contained within a device prohibiting direct measurement at the point of origin
- IR temperature measurement is subject to significant errors due to atmospheric conditions such as wind, solar gain and moisture
- The temperature of electrical exceptions can increase dramatically and without warning if arcing should occur
- Qualifying exception severity based upon temperature does not consider the potential impact of an unplanned failure
At present, there is no scientific method for accurately predicting time to failure based upon operating temperatures of electrical or mechanical components. In order to reduce the likelihood of an unplanned failure, every exception detected should be investigated for cause and properly repaired as soon as possible.
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An Emittance Greater Than 1.0 ?
Tip written by: Infraspection Institute
According to the laws of physics, only a perfect blackbody may have Emittance of 1.0. Although the E value of real objects must be less than 1.0, some radiometers allow entry of E values exceeding 1.0. The following describes how these radiometers achieve the impossible.
Emittance is a measure of how well an object radiates energy when compared to a blackbody at the same wavelength and temperature. Emittance for any object is measured on a scale between 0 and 1.0. Since blackbodies (E=1.0) exist only in theory, real world objects will have E values of less than 1.0. The E value of an object can never exceed 1.0.
Assuming that most objects are opaque (T=0), they must be somewhat reflective. When making an infrared temperature measurement, this reflected energy represents an error source. To overcome errors due to reflections, quality radiometers have inputs for reflected temperature. By measuring reflected temperature and entering this value into the radiometer’s computer, this error source is compensated for in the radiometer’s software.
Less sophisticated radiometers often lack inputs for reflected temperature. To compensate for this, these radiometers allow the user to exceed E values of 1.0. Although this overcompensation may allow the user to match a desired reference temperature, it can lead to significant errors. For infrared temperature measurement, the best solution is to use quality radiometric equipment and eliminate or avoid reflections whenever possible.
Emittance and proper imager 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
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Affiliate Marketing – How to Turn Your Website into a Profit Center
Tip written by: Infraspection Institute
As the worldwide web has matured, websites have become a business necessity filling a key role in the marketing, promotion, and sales of many companies. In addition to direct sales, websites can generate additional revenue through a concept known as affiliate marketing.
Affiliate marketing represents one of the newest opportunities for websites to generate revenue. With the right content, affiliate marketing can generate sufficient revenue to turn an existing website into a profit center.
Affiliate marketing is a system of revenue sharing between websites. The primary participants are an Affiliate Partner and an Advertiser. With affiliate marketing, the Affiliate Partner features ads and content on his/her website that refer traffic or sales to an Advertiser’s website. The Affiliate Partner receives a fee based upon amount of traffic or sales generated for the Advertiser’s site. Simply defined, Affiliate Marketing is risk-free advertising that rewards performance.
Examples of highly successful affiliate marketing programs include Amazon.com and Google. Under the affiliate marketing concept, everybody wins. Advertisers gain exposure, Affiliates enjoy commissions and increased website relevance and traffic, and customers find new products and services via familiar websites. With the right ads, Affiliates can actually generate a positive cash flow for their website.
The Infraspection Institute Affiliate Partner program allows thermographers to turn their website into a profit center. The Infraspection AP program utilizes state-of-the-art software to automatically feed non-competitive ad content to your website. When customers place an order for any Infraspection product or service, Affiliate Partners earn a 5% commission. Best of all, the Infraspection AP program requires no capital investment and can actually help to increase your website’s prominence and traffic! For more information, call us at 609-239-4788 or visit the Affiliate Partner area of our website at
