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.

Vibration Analysis in Maintenance

Can your technicians make the replace-or-repair decision?

If you engage in any maintenance, you will want to ensure your technicians can make the replace-or-repair decision before complete system failure of key components takes place. The easiest way to manage this risk is with vibration analysis.

Vibration analysis allows you to detect early signs of machine failure/deterioration. This allows your technicians to replace or repair machinery before catastrophic system functional failure takes place. Read more

Poor bearing lubrication identified and immediately remedied

Here is a great example from James Sylvester of how visually helpful the new Emerson 2140 PeakVue Plus is while working on site.

On a recent survey of a critical 110KW blower motor we noticed the PeakVue levels had increased. While at the machine we quickly ran the PeakVue plus and this highlighted the issue as a poor lubrication condition.

Instead of writing this in the report then living in hope the motor is correctly greased, we showed this at the machine to the site fitter and we were immediately permitted to lubricate the bearings and the levels reduced. Read more

Dynamic Vibration Absorber

BONUS: This is the 6th and final (free) case study in the series on Enhanced System Reliability.

In this sixth case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, shows how the use of Dynamic Vibration Absorbers can effectively reduce vibration levels. This case study covers a 2-year project period from initial root cause diagnosis to designing, trialing, and implementing an innovative cost-effective solution. Read more

23RPM Defect on a 4 Point Contact Bearing

This was to be the final of the five case studies on Enhanced System Reliability by James Sylvester. But, following on from feedback we will have one more case study next week, this will be an extra long project case study!

In this fifth case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, demonstrates vibration analysis of a slow rotational 4 Point Contact Bearing, with a 23RPM Defect. This is to remind us that correct database set up, and Time Waveform Analysis is so important in slow rotational bearings. Read more

Vibrating Screen Gearbox Bearing Defect

This is the fourth of five video case studies on Enhanced System Reliability by James Sylvester.

In this fourth case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, shows how it’s possible to diagnose faults on a vibrating screen. We demonstrate that by measuring the correct vibration parameters you can resolve defects in harsh applications, even an inner raceway defect on a vibrating screen. Read more

Variable Frequency Drive Deterioration

This is the third of five video case studies on Enhanced System Reliability by James Sylvester.

In this third case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, shows how analyzing vibration and thermal data can diagnose electrical drive faults. Read more

Standby Fan Motor Bearing Defect

This is the second of five video case studies on Enhanced System Reliability by James Sylvester.

In this case study from his book “Enhancing System Reliability Through Vibration Technology”, James Sylvester from JPS Reliability and an Reliability Training Institute Trainer, shows how analyzing bearing damage can lead to the root cause of the problem. Read more

Electrical Vibration Problem

This is the first of five video case studies on Enhanced System Reliability by James Sylvester.

In this first case study James shows how vibration analysis can be used to diagnose electrical vibration problems. In this case a VFD driven Motor. Over the next few weeks James is going to share a selection of interesting vibration analysis case studies. Enjoy, and please share if you found it useful – thanks. Read more

ABSTRACT – Vibration Analyst Checklist

Practical advice is given on getting the most meaningful and the most accurate information from machine vibration analysis, viz. on identifying the appropriate measurement locations and axes, the optimal data collection settings and the best analysis techniques. Also stressed are the importance of good reporting practices and the desirability of root cause analysis and acceptance testing.

INTRODUCTION

Vibration analysis is a fantastic field. For the analyst it is challenging and stimulating, and it should be rewarding. For the employer, it offers great financial rewards. But the question is: are you taking full advantage of the potential of vibration analysis? On the face of it, it can seem pretty simple. If you follow the set-up recommendations of the data collector vendor, and make sure that you mount the sensor on the bearing, then you will capture a spectrum that looks about right. It will have peaks and patterns which make it look like the spectra you see in the case studies. So you must be doing it correctly, right?  Not necessarily. Read more