Thermography provides the means by which ongoing preventive maintenance can be carried out. It enables engineers to inspect vital HVAC equipment, cooling systems, electrical switchgear, power distribution units (PDU) and other electrical devices quickly and easily. Thermal imaging, or infrared thermography, visualizes and measures infrared radiation emitted from objects. This technology can therefore be applied in any application where the performance or condition of a component can be revealed by means of thermal difference.

What an IR camera shows
The amount of infrared radiation emitted by a surface depends on both its temperature and its emissivity. Surfaces that are good reflectors (e.g. polished metal) are poor emitters, while surfaces that are good emitters (e.g. human skin) are poor reflectors. The emissivity of a surface is the ratio of energy radiated by that surface to energy radiated by a black body at the same temperature. Infrared energy makes up one part of the electromagnetic spectrum.

The naked eye cannot see infrared energy because it is emitted from objects as heat, not as light. The hotter an object, therefore, the more thermal energy it emits. Infrared thermal imaging cameras provide a visual representation of IR energy emissions. Where quantitative information is required, the thermal camera can also provide accurate surface temperature values of the object being viewed. The images generated can then be saved for later analysis and report generation.

Electrical parts that are damaged or about to fail will emit heat. The thermal camera detects any excessive heat in relation to the ambient temperature. For data centre maintenance engineers, thermal imaging technology can help:
•     check for loose or
over-tight connections;
•     identify overloaded components;
•     evaluate uneven voltage distribution; and
•     recognize failed or fatigued components within a distribution system without having to isolate circuits.

As an example, let’s look at a specific component of a data centre’s electrical infrastructure: switchgear. It is not unusual for switchgear to experience surges in current that can lead to connections working themselves loose. This problem can go undetected when relying on the naked eye to notice it. Poor connections can lead to loss of connectivity, overheating, fires and power outages—all of which would be potentially disastrous. Using thermal imaging, it is possible to identify hotspots within switchgear to detect potential problems, and allow the engineer to repair them.

The benefits of deploying thermal imaging to the data centre are significant. First, because it may be possible to avoid shutting down the facility to fix the detected problem, there is no disruption to normal operations. Second, regular monitoring with thermal imaging cameras to ensure the data centre’s power distribution boards, isolators and automatic switching panels are in working order can help the business comply with regulations.

In addition, regularly checking the system will lead to better diagnosis of any problems and enable maintenance engineers to formulate a more effective plan of action to overcome issues. Also, the use of real-time data provided from regular monitoring can extend the life of the system and result in significant cost savings. By identifying the inevitable degeneration of power equipment, replacement activity can be planned at the optimum time, avoiding major disruption.

Infrared imaging for saving energy
Along with using thermal imaging for preventive maintenance, the technology offers significant energy saving benefits. Green issues are prominent in the data centre industry. Analysts estimate that the increased shift towards cloud computing will triple the information and communications technology sector’s energy consumption by 2020.

Companies can achieve major cost savings by identifying areas where they are losing energy. Thermal imaging can provide a complete picture of a building envelope and its energy performance or, more specifically, a particular zone, room or piece of equipment. For example, it is possible to scan computer rooms to identify problems like overloaded racks and power cables, or even when IT equipment is placed backwards and is blowing hot exhaust back into a cold aisle. This can have a dramatic impact on the efficiency of the cooling system. The same can be said for when cold air escapes under a rack where a brush grommet should have been placed.

When thermal imaging is used to assess cooling systems and heat generating equipment it allows engineers to locate zones and the degree to which temperature-controlling units are actually cooling or heating the room. Systems then can be arranged for optimal performance, helping to increase the premise’s energy efficiency and lower operational costs.

Enhanced ease-of-use coupled with lower prices have made thermal imaging cameras standard equipment for in-house maintenance engineers. Where once a data centre would employ a specialist to carry out formal checks, in-house engineers can now do regular preventive maintenance and energy efficiency auditing themselves. In many cases, it only takes one problem to be identified and fixed for the thermal imager to pay for itself.

Infrared camera selection considerations
There are a number of key features to look out for when selecting a thermal imaging camera. Primarily, the quality of the image should be a major consideration. Owing to technological developments, it is now possible to find a device that delivers an exceptional high-resolution thermal image at an affordable price. Another important consideration is a detector that is fully radiometric, meaning it will capture temperature measurements over the entire image.

Image fusion allows the user to view the subject as either a digital or a thermal image, or a blend of both. By combining visible and thermal images, the user is able to get a clear image of the equipment being monitored while easily seeing potential faults.

Temperature sensitivity is also a key feature to look for when choosing a thermal imaging camera because it can affect the accuracy of the temperature measurements. The industry standard for temperature accuracy is ±2ºC.

Thermal imaging has become an accessible technology that is enabling data centres to replace traditional maintenance programs with predictive maintenance strategies. In addition, with the green agenda high on data centres’ agendas, this technology can help comply with energy efficiency obligations.

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Article contributed by Ideal Industries Inc. This was originally published in Electrical Business magazine.

FLIR has announced that ES Gallagher and its Ontario sales force has joined the FLIR Canada sales team. The ES Gallagher sales team will be working as FLIR sales agents with all of the thermography manufacturer's industrial and MRO distributors in Ontario.

ES Gallagher will be conducting the traditional expected FLIR sales services, including counter mornings, lunch-and-learn seminars, joint sales calls and demos, providing clients with the expected FLIR support. All ES Gallagher sales reps are Level I Thermographers, with more than four years of experience in selling both FLIR and Extech products.

ES Gallagher, established in 1933 as a manufacturer of oil-heat products in Toronto, has evolved into a leading Canadian distributor of high quality HVAC/R and plumbing components from around the world. In 2008, ES Gallagher became Canada’s No. 1 distributor of Extech test and measurement products for the HVAC/R market with continual growth. Now ES Gallagher will be focused on developing and expanding your FLIR IR and Extech T&M business.
www.flir.ca
www.esgallagher.com

A plant engineer’s ability to diagnose, detect and monitor equipment condition issues is advancing all the time, thanks to ongoing developments with vibration, thermography (infrared), oil analysis and ultrasound tools, just to name a few.

So once you have all the fancy new tools, do you know how best to take advantage of them?

We’re here to help. Along with the sophistication of the tools available, ways to synthesize and integrate data so that maintenance teams can make immediate use of it and also monitor trend issues over a period of time are also progressing. PEM asked leading technology providers to share the latest in their condition monitoring tech developments, how best to integrate them, and where the future is headed.

Infrared
Over the last few years, infrared cameras have improved significantly in terms of resolution and now come with more options as well, says Paul Frisk, manager of the Infrared Training Center in Burlington, Ont. (the training arm of infrared camera-maker FLIR Canada Ltd.). “Infrared cameras now have the ability to incorporate wireless data from digital clamp meters and other instruments and make that all available at one glance,” he explains. “Some cameras now available immediately generate a single-page report. This summary can be transferred for printing and archiving by download to an office computer or through wifi to a plant’s CMMS system.”

Frisk says the primary value of an infrared camera is in its ability to initially determine whether a device is working properly or not while it’s running. “With some other diagnostic tools, you have to shut down the device, which obviously impacts production,” he notes. However, as with many types of detection and monitoring technology, there are misconceptions about what infrared cameras can provide.

“From watching movies and TV, people think infrared cameras can allow you to see through walls, water, etc., but they only measure released infrared energy,” he explains. “A properly trained thermographer can determine temperatures from infrared readings using conversion factors, knowing the material and so on, but infrared cameras cannot overcome the physics of all materials under all conditions.” He also stresses that infrared images can easily be misinterpreted, and proper training is absolutely necessary.

In addition to using handheld infrared cameras and connecting them with your plant’s CMMS, standalone infrared cameras can send data to the process PLC (programmable logic controller). “Based on the camera’s readings, things like process speed, fans or heat can automatically be adjusted if the material needs to be kept at a certain temperature,” Frisk notes.

With regard to the future of infrared condition monitoring technology, he foresees more improvement in resolution and smaller camera size, along with a continued drop in cost.

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Ultrasound
Ultrasound instruments have changed a great deal over the past decade, according to Alan Bandes, vice president of marketing at UE Systems. Analog detectors, which required manual entry of test results for basic trouble-shooting, have been replaced by software-driven digital systems capable of analyzing trends and reporting on a wide range of operating conditions. Newer models offer things like sound analysis, cameras, non-contact infrared thermometers, and even touch screen controls. “There are a lot of professionals that haven’t looked at ultrasound technology closely and view the instruments as basically leak detectors,” Bandes says. “Others feel, incorrectly, that ultrasound is too subjective, which is often due to experience only with older analog units.”

Bandes says it’s very easy to integrate ultrasound technology into plant processes. “Due to the sophistication of on-board software and external supportive software, users can create routes, establish baseline information and upload and download route data,” he explains. With baselines set, the software can notify personnel with low-level alarms (for example, lubrication starvation) or high alarms (failure) through headphones or other means.

Some instruments provide inspectors with the option of opening up a spectral analysis screen to analyze bearing faults, gear mesh issues and electric emissions while in the field. Recorded sound samples can be played in real-time and viewed with an image of the spectral screen. “This feature is very useful for electrical emissions as well as mechanical operations,” he notes.

Software associated with ultrasound instruments can provide specialized reporting for things like steam traps, valves and bearings. “Regarding leak surveys, downloaded test results can be converted into reports that provide important information for cost analysis and greenhouse gas emissions,” Bandes says. Regarding the future of machine monitoring by ultrasound, he believes “we are only limited by the software we can develop.”

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Oil analysis
More vendors now supply in-plant oil analysis sensors and the means to communicate with those sensors. “It's no longer necessary to rely solely on a lab for analyzing oil samples to determine fluid condition,” says Darren German, Bosch Rexroth national service manager. “In the plant, we can now get real-time results on of oil cleanliness (particle count), water content and temperature when sensors are coupled with a data acquisition device.” These devices can record and track trend parameters in real time for any given time period, but German cautions maintenance teams that monitoring equipment should be considered as a compliment to a bottle sampling program; reports from an oil analysis lab still provide the most oil condition information. The role of monitoring equipment is to provide additional protection between bottle sampling periods, he says. “If, for example, a heat exchanger ruptures and releases water into the oil the day after a bottle sample was taken,” he notes, “this will likely go unnoticed until production stops if there is no oil analysis sensors in place.”

The many oil-monitoring systems on the market range in complexity and price. “Some of the data acquisition systems also provide the ability to add a threshold or alarm which will signal the moment the results vary from a ‘baseline normal,’ ” he says. “We suggest that before investing, you should understand what it is that you want to accomplish — what parameters are important to monitor.” He recommends that maintenance groups consult with their engineering groups prior to purchasing a system, as the ability for a machine to communicate with a sensor often already exists within the machine HMI.

German predicts that down the road, the capacity to measure reliable viscosity and TAN (total acid number) will be developed, along with a sensor that can measure the amount of air in hydraulic fluid. “ ‘Smart’ sensors and wireless sensors are often mentioned as coming down the pipe as well,” he says.

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Vibration
Advances over the last few years in sensor, recording, and analysis technology have put vibration analysis within the reach of even small companies, says John Bernet, product and application specialist at Fluke Corp. “Easier measurement procedures (triaxial sensors), combined with vibration diagnosis programs (expert systems) now enable maintenance teams with minimal training and experience to use vibration to evaluate machine health and determine required maintenance,” he notes.

Bernet says vibration can identify problems before other symptoms, such as heat, sound, electrical consumption and lubricant impurities, are detected. “Measuring the vibration of motors, pumps, and other common machines can reveal valuable information about machine health or impending failures,” he notes. “However, instead of focusing on the patterns of the hundreds of faults that vibration analysis can reveal, we should focus on the four most common mechanical faults: imbalance, misalignment, wear, and looseness.” He adds that studies have found that many vibration analysis programs don’t collect all the data needed to make an accurate diagnosis — to diagnose machine condition correctly, vibration data is needed from all three axes of a rotating shaft.

The key to automating vibration analysis, he notes, is to compare new data with data from a similar machine known to be functioning properly. Automated diagnostic programs perform a sophisticated analysis, comparing hundreds of data points with the fault patterns of similar machines to give easy-to-understand results.

Bernet foresees that the benefits of vibration analysis will be expanded to the entire plant in future. “A plant’s reliability team can use high-end analysis programs on the few complex machines, while the maintenance team can use simple diagnostic tools on the basic machines,” he says.  p

Treena Hein is a freelance writer based in Pembroke, Ont.