infrared thermal imaging to fix common misalignment

Last Updated: April 21, 2021

Infrared Thermal Imaging is useful across many industrial sectors

Hi! I’m Craig Smith, a Reliability Engineer at RMS. Over the past few years I’ve been using Infrared Thermal Imaging technology to great affect, helping customers diagnose and repair maintenance issues with higher degrees of accuracy and speed.

This article is based on a planned electrical maintenance survey of panels and distribution boards looking for any irregularities. This consists of cables, cable connections, breakers, inverters and control boards.

Our Infrared Thermography service is a predictive maintenance inspection technique that is widely-recognized and an effective non-destructive (NDT) testing tool used often to check electrical and mechanical systems, buildings, roofs and facilities.

Traditional methods of detection

The traditional method for identifying an electrical connection or component problem is the use of an infrared camera when it is under load. However, there is misunderstanding about how to establish the condition of the connection once a thermal anomaly has been found.

Historical methods of Infrared Thermal Imaging have applied the use of temperature, or temperature rise, using the infrared camera, as an indicator of the defect severity. Infrared, however, only identifies surface temperature rather than internal interface temperature.

The value of Thermography is being able to identify that a thermal anomaly exists

While thermography can identify a connection problem through the thermal pattern, the connector surface temperature can be a poor indicator of the nature of the problem or its severity.

How do Thermal Imaging cameras work?

The A0404B1 Infrared Tachometer is recommended for indoor/outdoor use. When used with Emerson’s Machinery Health Analyzers, the phototachs provide a tach reference signal for applications that include measurement of turning speed, synchronous time averaging, machinery balancing, phase tracking, and coastdown/startup analysis.

Where can Infrared help technicians?

Now that we’ve briefly explained the importance of Infrared Thermal Imaging, let’s look at exactly how thermography helps in maintenance.

Key components that thermographic analysis can detect problems with include, but not limited to:

  • Misalignment
  • Bearing health
  • Steam/Water Leaks
  • Turbine machinery
  • Bent shafts
  • Solar panels
  • Moisture
  • Loose bolts, mounts, fasteners, etc.
  • Electrical issues
  • Process flow issues

Top tips when taking a thermal image

  • Understand the surrounding parameters:
    • shooting an image with sunlight or a reflective background (inside panels) will give you bad data
    • also if you are in a panel room and the AC is on
  • Stand at 45* to the object of interest and use multiple angles if possible
  • Adjusting the Emmissivity and Reflected temperature accordingly is a must, or you will get bad data
  • Using a known source of black body:
    • carry electricians’ tape with you and put a piece on the object if safe to do so
  • Don’t ignore small temperature differences:
    • if you are looking at two objects close together one may be quite a lot hotter than it appears on the image
  • Focus on the object and thermally tune the camera to suit using the temperature adjustment

Problem awareness

  • Connections problems occur when fitting lock screws that are under-torqued or Over-torqued
  • Incorrect cable sizing for breaker etc, wrong size lug connections or not lug at all
  • Cable insulation not cut back enough
  • Poor soldered joints.
  • Excessive vibration in the area,
  • Process patterns with stop start or VSD motors
  • Environment issues such as heat or steam, corrosives
  • Always have a good scope of the area you are working in and a good visual of what you are looking at

Recent images explained

The CAT I Vibration Analysis course includes a topic on Thermography. The course is designed for reliability engineers, PdM program managers, and other maintenance staff who would like to understand condition monitoring with a core focus on vibration analysis.

If you have any questions about the role of thermal imaging in maintenance and how Reliability Maintenance Solutions can help you, please feel free to contact us, or leave a comment below.

FAQs

Historical methods of Infrared Thermal Imaging have applied the use of temperature, or temperature rise, using the infrared camera, as an indicator of the defect severity. Infrared, however, only identifies surface temperature rather than internal interface temperature.

Key components that thermographic analysis can detect problems with include, but not limited to: Misalignment, Bearing health, Steam/Water Leaks, Turbine machinery, Bent shafts, Solar panels, Moisture, Loose bolts, mounts, fasteners, etc., Electrical issues, Process flow issues.

Don’t ignore small temperature differences. If you are looking at two objects close together one may be quite a lot hotter than it appears on the image.

13 replies
  1. Steve D
    Steve D says:

    Many thanks for sharing! As I’m new to Infrared and Thermography, I was excited to find this post on LinkedIn. The article has got me excited to learning more. The FLIR video was really insightful. It truly is amazing technology.

    Reply
  2. Erik Thorup
    Erik Thorup says:

    Hi – Thank you for the information. Good to see that the CAT1 V/A course includes IR, BUT I strongly suggest that ANYONE who uses Thermography for Con Mon ALSO attend CAT1 Infrared Training (and Certification). For IR in Mechanical Systems, it is OFTEN necessaary to have a baseline, as it is with VA, although ad hock fault finding is possible to some degree. Electrical Thermography is a “much easier target” to survey and analyse. I suggest that you try to compose your images better, filling up the image with informative information AND also getting as close as possible, and for example take your images more horizontal/vertical and not on a skewed angle. Turning the camera 90 degrees can often give you a better image and fill grade of the areas of interest, and therefore better measurement as well. For many electrical components, looking straight on will usually give you the best chance of comparing load and line side, BUT it will never give you the highest fault temperatures if you take them from the image tools in that image – so it can be difficult to get all the information into ONE image only. Keep learning and keep training. Keep up the good work.

    Reply
    • Support
      Support says:

      Hi Erik. Thank you for taking the time to share your thoughts and for the supportive nature of your comment. Yes, good call to mention the CAT I infrared Training, especially for those looking to go beyond an introduction to IR. We currently don’t offer that course, but perhaps that will change in the future. Craig will likely post a reply to your tips and suggestions in the coming days. To concur, learning IS the work 😊

      Reply
    • Craig Smith
      Craig Smith says:

      Thanks for taking the time to visit the post and for sharing your tips. I’m looking forward to seeing some of your photos and IR insights on channels like LinkedIn. Have a great day.

      Reply
  3. Erik Thorup
    Erik Thorup says:

    NOTE: you mention “Don’t ignore small temperature differences: if you are looking at two objects close together one may be quite a lot hotter than it appears on the image” One reason for this MAY be that FLIR uses Histogram Equalisation when working in the Automatic Mode, and this MAY cause the colour palette to become non linear, and SOME temperature differences MAY not show up very well. FLIR do not tell you this, but it has caused SOME faults to go undetected, and allegedly some electrical fires have ensued. You need to be VERY vigilant and change to the linear mode, you need to go into the MANUAL mode and start changing the level/span to start LINEAR mode to work. Also ALWAYS work with an Area Max (or Min) in the image as this will help in this case.

    Reply
  4. Tyler Johnson
    Tyler Johnson says:

    That’s interesting that it could be used to identify electrical issues. I could see how that would be useful since I assume you wouldn’t have to tear down any walls. Looking for an electrician that uses thermal imaging sound like a good idea to me.

    Reply
    • Craig Smith
      Craig Smith says:

      Hi Tyler. Yes, we use infrared for a lot of electrical surveys, mostly we survey every 6 or 12 months as part of the maintenance program. We look for stand out defects/hot-spots but also trend specific assets such as transformers. If you can open panel doors safely you can use infrared for electrical surveys. Personally I think it is the best way to do so. If you need anymore information please get in touch via the contact link.

      Reply
  5. Taylor Hicken
    Taylor Hicken says:

    Thank you for sharing that thermographic analysis can detect problems related to the operations. In this way, companies will be able to identify the issue when there are any flaws during the manufacturing process. I would like to think if a company is having issues with its equipment, it should consider working with a reliable service that can conduct infrared thermography.

    Reply
  6. Jonathan Apperley
    Jonathan Apperley says:

    Great post! I work within an industry that makes use (and supplied) thermal imaging technology to consumers and I found this very informative, especially the video.

    Reply

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