Infrared thermography can be a valuable tool in the hands of the right person. Certified thermographers offer an inside track to troubleshooting or predicting problems. And that translates into increased profitability from increased equipment uptime and avoided failures. But the technology doesn’t work by itself. Don’t follow the path of so many plants, where an infrared camera was purchased years ago, but now it sits in storage because the program lost momentum or the individual with IR expertise left the company.
Circumstances differ from plant to plant, but managers need to decide whether to bring IR thermography in-house as part of the condition-monitoring responsibilities of maintenance, reliability, and operations or to contract those services.
“In general terms, the decision to do thermography in-house or to outsource is based on the size of the company or facility,” says Brad Gilbertson, an Infraspection Institute certified level III infrared thermographer at Sandhills Thermal Imaging. “For smaller facilities, it might not be worth the expense to spend the money on the equipment, training, and administrative requirements of an in-house thermography team. Does the company have enough potential work to justify the expense of an in-house team? The purchase of an imager is usually the only figure anyone looks at. They forget that human capital is much more important. If a company decides on an in-house solution, they will need to invest in proper training for the personnel, as well. It may be that a facility manager may decide that the IR program will consist of a dedicated maintenance team who will regularly work with a contracted thermographer who visits the plant on a set schedule.”
Gilbertson’s larger clients tend to have their own in-house thermography teams as part of maintenance. “The advantage of having a thermographer in-house is they can use thermography as part of their regularly scheduled maintenance program,” he explains. “That thermographer may also be used for condition monitoring or to check equipment after repairs have been made. The thermographer is always available whenever needed.
No one ever thinks about the administrative costs when they simply purchase an imager as part of the thermography program. If a thermographer goes out into the plant and spends a number of hours imaging, he will then spend several hours writing reports. So, know a maintenance tech is spending time writing reports and not performing other tasks. Contracting an outside thermographer puts the report writing in the hands of the contracted company. The contractor comes in, does the imaging, and leaves to write the report. The maintenance department helps with the survey but is not tied up with any administrative tasks afterwards.”
Figure 1. Learning curves need to be traveled when using new technology and setting up system requirements.
The in-house vs. outsourced answer would be directly related to the time and capital resources that can be assigned to building a competent IR monitoring program, advises Kevin Lesnewski, product manager at the thermal imaging division at Testo. “As with any new program there are learning curves that need to be traveled when using new technology and the setting up of the system requirements,” he explains (Figure 1). “Basics include what to inspect, when to inspect, creating report templates, tracking of observations, issuing work orders, and tracking repairs; they all need to be defined and SOPs developed. If the resources can be assigned to develop the program, in the long term, costs are reduced and internal competence is built and expertise is developed. If not, the shorter-term approach of hiring an IR survey company to look at specific operations is a sound approach but it can cost more in the long term.”
Not every plant has the historical basis for cost-justification of the time and equipment, says Tony Shockey, thermography product manager, Fluke. “Five to 10 years ago, it could have cost $30,000-$50,000 for the camera alone, not adding in the cost of the individual, the training, and the full report based on the number of applications,” he explains. “Now that the cost and technology have improved greatly and the training requirements have decreased with ease-of-use, more facilities can see an ROI in just days, first by conducting a thorough inspection, finding small to large issues before they start to cost the company money, and then by having the inspection tool on hand to problem-solve faster, increasing overall maintenance productivity compared to an annual inspection.”
Given that most issues for electrical or mechanical will result in a rise in temperature, once an in-house team does its homework and establishes both level of criticality of equipment and then baseline images for each, then the entire team, not just those with tribal knowledge of specific equipment, can effectively assess conditions, says Shockey. “With a thermal image, the technician can quickly identify areas of concern and focus effort at those areas that show a difference in temperature vs. the historical or known temperature,” he explains. “The advantage of contracting speaks largest either for facilities with fewer critical machines or large electromechanical loads. In that case, it may be sufficient to have a level III certified thermographer performing the work and generating a report with all necessary information to present you with all of the findings.”
With the cost of infrared imagers coming down dramatically, there has been a move by many companies, who had previously hired all of their infrared inspections done by an outside company, to begin to move some or all of those inspection programs inside, explains Alan Clark, applications engineer/sales support, T/IRT level II thermographer, Palmer/Wahl Instrumentation Group. “The cost of one or two inspections, depending on the size of the organization and depth of the inspection, could pay for one or more imagers for internal use,” he says. “It soon became apparent to many of these companies who did bring the program inside that it really was not a simple point and shoot and find the problem issue. Things that appeared bad were not always so and things that looked OK turned into problems. Many made the decision to bring the professionals back in and some made the decision, instead, to get their own people properly trained, to make them the professionals.”
Figure 2. Becoming a professional thermographer is more that just attending some classes and getting a certification by passing some tests.
Becoming that professional is more that just attending some classes and getting a certification by passing some tests, cautions Clark (Figure 2). “In critical industry applications, especially in dealing with high-voltage power applications, these ‘newbie’ certified individuals needed some time with an experienced old-timer, maybe from an outside company if there is not one inside, to develop a level of expertise under sometimes hazardous conditions,” he explains. “It’s very easy to get killed or severely injured by high-voltage arcing and explosions.”
In his career, Clark has called on numerous power plants that had a $60,000-$80,000 imager on-site but only one person, who’d gone through extensive training, was allowed to touch it. “Plant engineers and operation managers were highly interested in the new, lower-cost imagers to put in the hands of maintenance people on all three shifts, just to look for things that appeared out of the ordinary,” he says. “If they found a problem, they were simply to report it to their supervisor, and the supervisor would get the ‘pro’ with the big camera to take a real look at it. Most power plants have developed their own in-house program for security reasons, also.”
Who needs it?
Every technician, mechanic, and electrician needs to measure temperature, says Gary Orlove, P.E., curriculum manager/application engineer at the Infrared Training Center (ITC) and InfraMation Thermography Conference co-chairman. “A thermal imager is a temperature measurement tool that also shows you your environment thermally and allows you to see where to measure,” he says. “There are great thermal imagers now that start under $1,000, so the question isn’t in-house or contract, but what is the best tool to measure temperature? The advantages of thermal imaging are greater safety, speed, accuracy, and documentation. During inspections we’re looking for equipment that is going to fail. Being able to see your environment thermally can quickly alert you to potentially unsafe conditions. Compared with traditional measurement tools like contact thermometers and IR temp guns, a thermal imager will show you temperature differentials in real time, so you see problems immediately. Thermal imagers measure a smaller spot than spot temp guns to measure more accurately and from farther away, which makes them safer. Thermal imagers store an image with the temperature data, date and time, and for some models voice and text notes to document faults.”
Figure 3. Having the equipment in-house enables companies to monitor equipment performance and conditions on a periodic basis, which allows organizations to detect emerging issues well in advance of equipment failure.
Having the equipment in-house enables companies to monitor equipment performance and conditions on a periodic basis, which allows organizations to detect emerging issues well in advance of equipment failure so maintenance and repair can be scheduled during off-peak shifts or scheduled downtime, explains Orlove (Figure 3). “For PdM programs, thermal diagnostics can provide insights into equipment performance and reliability, so that plant mechanics and engineers gain a clearer understanding of predictive maintenance needs on the shop floor, including trending analysis and documentation,” he says. “This can be invaluable when maintaining, upgrading, and designing modern equipment that relies on an interconnected, complex array of electrical, mechanical, electronic, pneumatic, heating, hydraulic, computer, and robotic systems.”
The right tool
Two types of infrared thermography are widely used in industrial and manufacturing facilities: thermal imaging cameras and scanning infrared thermometers (IRTs), explains Karen Kwong, product development engineer, General Tools & Instruments. “Used separately or together, these devices help to quickly and easily assess the thermal condition of machinery, process systems, and more,” she says (Figure 4). “Plus, their ability to do so safely and accurately from a distance is particularly useful for components and systems that are hard to reach, inaccessible, or hazardous. The decision whether to bring infrared thermography in-house or contract with an outside vendor depends on a variety of factors.”
Figure 4. Used together or separately, thermal imaging cameras and scanning infrared thermometers (IRTs) help to assess the thermal condition of machinery and process systems.
Today’s scanning IRTs are affordable and easy to use, says Kwong. “It’s probably more cost-effective to invest in the equipment in-house as opposed to contracting a service,” she says. “An important factor to consider when purchasing scanning IRTs is the distance-to-spot (D:S) ratio, which is the ratio of the distance to the object and the diameter of the temperature measurement area. For instance, if the D:S ratio is 8:1, measurement of an object 8 in. away will average the temperature over a 1-in. diameter area, while measurement of an object 8 ft, or 96 in., away will average the temperature over 12-in. diameter area. Higher D:S ratios allow for higher accuracy over a greater distance, but IRTs with higher D:S ratios tend to cost more.”
Another important factory is the emissivity of the IRT, says Kwong. “Less expensive models usually have fixed emissivity at 0.95, which covers most applications,” she explains. “However, for measuring surfaces with lower emissivity levels — such as aluminum, brass, and copper — you need to be able to adjust the emissivity. If you’ll be measuring such surfaces routinely, you’ll want to invest in an IRT that offers the adjustable emissivity you need. You’ll also want to consider whether or not the IRT allows the user to establish a reference temperature set point and a tolerance range relative to that set point. Models with this ability alert the user to areas where the temperature reading is within or outside the acceptable range.”
Because there are advantages to in-house thermography and to contracted services, Gary Lux, managing partner at Cold Mountain Infrared suggests taking advantage of both. “Using a combination of both approaches provides the best solution,” he offers. “In a combined approach, the company maintenance personnel can be trained to perform basic level I thermography inspections as part of routine maintenance. But the liability of the level II and level III inspections is passed to the professional thermographers.”
Annual inspections
Hiring an outside contractor to do a quick shoot-and-scoot inspection just to satisfy your insurance requirements is not smart, says Cold Mountain’s Lux. “That contractor is not doing you any favors,” he warns. “The primary focus should first be on safety and determining the true consequences of failure. This means that not only should you be imaging your known critical components but also your potentially critical components. Be especially aware of parallel component systems that have been designated as run-to-failure (RTF) components. Historically, there have been some RTFs that have resulted in disastrous consequences. The chances are that your plant already has potentially critical components that have already failed. This is a huge liability that can bring your production to a screeching halt. You can't pass that responsibility to an in-house level 1 thermographer.” Be sure you hire a contractor who really understands the concepts of potentially critical components and how PdM and reliability-centered maintenance are related, advises Lux.
If a company is willing to get people properly trained and help them build some experience, they are probably better off bringing the program inside where they can better control the actual inspection intervals and repair follow-ups, says Palmer/Wahl’s Clark. “Most companies who hire outside groups to do their surveys, have them come back at regularly scheduled periods,” he explains. “I have seen those intervals go from once each quarter to once every three years. The time intervals are largely based on companies with large numbers of electrically powered or belt-driven production machinery and large conveyor systems on large production lines where one failure could shut down an entire line. Those people check their equipment more often. Even if those companies continue hiring their surveys done from outside, the survey companies will then turn their reports of problem areas over to the plant manager who has the in-house maintenance crew fix the problems. Did the problems really get fixed? If the on-site maintenance people do not have their own imagers, they cannot check behind themselves to see if they really have the problem fixed. The real advantage to gradually bringing your maintenance program in-house is the ability to be constantly checking areas of critical importance, to routinely check areas that have had past periodic problems, and to do checks to see if repairs were completed successfully.” When new equipment is purchased, a thermal profile can be made of it, so that periodic checks will begin to show any changes that occur with wear, load, and time.
“The large companies, and the smaller ones, as well, hire me as part of their annual insurance requirements,” says Sandhills’ Gilbertson. “A big part of that function is the documentation. Yes, the independent thermographer is there to do the imaging, but in reality he’s being paid for a report that will be submitted to the plant's insurance company. It’s also been my experience that some insurance companies prefer the annual IR inspections be made by an independent third party. Having an independent thermography service perform the annual IR inspections is seen as preventing the foxes from guarding the henhouse. While some do not mind in-house teams, they want those teams to have the proper training and certifications to perform the task. It’s probably advisable to outsource the annual IR inspection, if the in-house team consists of a single person armed with an imager and only a Level 1 thermography certification.”
Where the question of in-house vs. contracting applies is with annual inspections of all systems in a facility, agrees ITC’s Orlove. “This is a longer survey vs. quick troubleshooting, and many companies will contract experts for the annual audit,” he explains. “These experts could be a shared corporate resource or an outside contractor. These experts are set up for surveying, analyzing, and documenting a large number of targets quickly.”
Where’s the heat?
If you’re going to use thermal imaging cameras in-house, you need to be willing to invest in the equipment, explains General’s Kwong. “While an individual thermal imaging camera typically costs more than a thousand dollars, it can pay for itself in a short amount of time, sometimes even at first use if it prevents a catastrophic machinery or system failure,” she says. “You also need to be willing to invest in proper training. Another consideration is your ability to properly and safely maintain and store the equipment. There’s no sense making the initial investment if you’re not prepared for instrument care. It’s also important to consider equipment specifications and features, such as camera resolution and focus, temperature measurement range, emissivity, on-camera analysis tools, software for advanced analysis, as they relate to your needs. One advantage to incorporating infrared thermography in-house is that the equipment and personnel are immediately available, so related tasks can be performed at any time. With a contracted service, you are dependent on the contractor’s availability.”
However, contracting with an outside service may be the way to go if the costs are significantly lower than investing in your own equipment and training, and if the logistics are substantially easier to manage, says Kwong. “If you opt for contracting, you’ll want to make sure you engage a reputable service that provides technicians who are certified to the level that meets your needs,” she explains. “And you’ll want to see proof of that certification. The advantage here is that certified technicians presumably know the equipment inside-out and are able to operate it efficiently and interpret results more quickly with a high level of insight. Having a grasp on the scope of how you plan to use infrared thermography at your plant and the frequency of its use is essential. If the idea is to use this technology on a routine basis to develop a more strategic and proactive approach to maintenance, then having the freedom to use the equipment at will in-house could be a huge advantage. For example, thermal images of a given piece of equipment or a specific equipment component can be captured at preset intervals and compiled over time. Such records can provide timely indications of deteriorating conditions and even help to make reasonable predictions about future deterioration, so the appropriate maintenance and repair can be done at the most appropriate time and in the most cost-effective manner.”
The use of IR thermography to inspect, troubleshoot, and diagnose problems while machinery is running, without interrupting processes, will help to improve the efficiency and effectiveness of component-specific and plant-wide operations and maintenance, providing opportunities for a quick ROI, says Kwong. It’s important to view either scenario — in-house or contracted —a strategic investment.