Thermal imaging topics that you would like to see on this forum?

[Fraser]

Hi all,

As some may know, I am a collector and repairer of thermal imaging camera technology. I try to post interesting thermal imaging related stuff now and then, but as a "Thermal Camera Geek" I am not sure what people really want to read about on this forum.

This is your opportunity to list the topics and/or technology explanations, that you want to read about. I cannot promise to fulfil the wish lists contents personally but there are many very knowledgeable and clever members on this forum who might be able to help.

Personally I am interested in the technology used within thermal cameras, old and new. I soak up as much information about such as I can lay my hands on. I am not an expert in the topic though. I leave that title to those clever people who design thermal cameras ! At least one of whom is a member of this forum. I also like to use thermal cameras to observe wildlife and for technical tasks such as PCB thermal profiling and even checking my cars engine and brakes !

I have a large collection of working thermal cameras and considered producing a thread that contained pictures of some, along with specs and examples of the thermal images that they produce. Sadly that is quite a time consuming task as many of the cameras have their own software packages for image download etc. I may yet produce such a thread but I have an inkling that such is not of great interest to many forum members who may be more interested in the current models of thermal camera. Sadly many people do not know much about the older industrial thermal cameras and their capabilities. That was an advantage when I was collecting them though. The latest thermal cameras are sold at very appealing prices so I suppose it Is understandable.

Fraser

[SeanB]

How about a series on the lenses, and how different lenses affect camera performance, for us dummies Fraser.

[chickenHeadKnob]

The volt nutters here would be interested in your opinions on equipment and methods to map heat flows on our ovenized contraptions. What in the current market is economical and optimally performant  for the role? It would need to have some advantage over manual placement of discrete temp sensors and slow data acquisition  which is what I am doing now.

[paradigmic]

How about a series on the lenses, and how different lenses affect camera performance, for us dummies Fraser.

Yeah, I'm curious about the different materials and why some are so much cheaper or more expensive.

[tautech]

Fraser, I'm a keen reader of your TI posts and what has wondered me is what model/makes would offer the hobbyist the best compromise of performance vs price for profiling and general faultfinding on the bench.

[sam1275]

I have a large collection of working thermal cameras and considered producing a thread that contained pictures of some, along with specs and examples of the thermal images that they produce.

I'm VERY interested in this!

[NathanFowler]

I've always enjoy your disassembly, break-fix, and explanations on IR technology.  I enjoy reading about the evolution in technology that you share with your older and newer equipment.

[Fraser]

Well this thread was visited 240 times since posting. It got six responses.

It would appear that many of those visiting the thermal imaging area of this forum are either very experienced on the topic or not that interested in such technology beyond buying and using it. Fair enough. I know that there are a few forum members who share my interest in both using and understanding the technology. Understanding the thermal camera design and correct usage can greatly enhance an owners experience with such, so this strikes me as a bit of a pity and opportunity lost.

I quickly knocked up a list of what I would have written in a post such as this when I first started out in thermography in the early 1990's I quickly got to 40 topics for discussion. I would have given my eye teeth fro the opportunity to learn about such a topic from others with knowledge of such at that time. It was very much a 'hidden' technology due to its military uses. You still will not find many in the industry willing to talk about the more technical aspects of current imaging technology.

It would be a lie to say that I am not disappointed with the response to this very open and inviting initial post. It would suggest a lack of interested parties on this forum on a topic that I enjoy discussing. It may sound selfish, but I no longer feel the drive to produce content in this sub forum such as camera tear-downs or FAQ's. If such has a tiny audience, there seems little point    I was thinking of starting a Yahoo Group for thermal imaging enthusiasts who actually want to know about the technology rather than just use it to take pretty pictures. That would then create a collective of like minded people who may learn from eachother. I may yet create such a group.

The EEVBlog Sub-forum is great and I am very grateful to Dave for creating this unique area for the discussion of thermal camera related topics. I shall contribute where able, but i think you will be seeing less new material from me from now on. I have 14 thermal cameras that I need to service or repair, along with a new 640x480 resolution 30fps DRS Ultra 6000 pan tilt thermal camera to play with  so there is much to occupy me at the moment.

For those interested, here is my initial list of 40 topics that I would have expected to appear after my initial Post, and most did not.


1. What is the difference in image quality produced by Pyroelectric Vidicon, BST, PZT and Microbolometers ? A review of the different technologies

2. Cooled Vs uncooled cameras, what are the differences in terms of maintenance and image produced?

3. What is the generic block diagram of a thermal camera ?

4. Help understanding Thermal imaging camera specifications. - the truth behind the 'marketing speak'.

5. What effect does the lens focal length have on the distance of detection and identification ?

6. What sets a thermal cameras temperature measurement range capability ? Can it be increased ?

7. Why is a thermal cameras more inaccurate when measuring very low temperatures below 0 Degrees C

8. What is the operational life of a microbolometer and what dictates such ?

9. Why are thermal cameras sold outside the USA often limited to only 9fps and is it legal to own a >9fps thermal camera outside the USA ?

10. Can a 9fps thermal camera be upgraded to >9fps ? What are the implications of such ?

11. Is it better to buy a used high end industrial thermal camera of a new consumer grade camera? What are the differences in performance ?

12. Fire Fighting cameras, are they any good for electronics and other tasks ?

13. What are the names of the main manufacturers of thermal cameras in the world. i.e. not just rebadged brands ?

14. What thermal cameras are best suited to specific tasks ? i.e. PCB inspection, Maritime roles, building surveys and wildlife observation.

15. Is buying  really cheap consumer grade thermal camera a false economy? why ?

16. What dictates the accuracy of measurements taken using a thermal camera ?

17. Is there a DIY option to build a thermal camera ? If so who sells such ?

18. Can a thermal camera be mounted and used on a Drone ? Recommended models ?

19. What is the field of view of a particular lens when used with different microbolometer die sizes ?  What dictates this ?

20. What are the different lens technologies and issues with such ?

21. How do you clean  thermal camera lens ?

22. Is it ok/legal to take thermal cameras abroad ?

23. Can a telephoto lens be added to a thermal camera ? How ?

24. What are the thermal camera industries dirty little secrets ?

25. Emissivity explained ?

26. How do you carry out PCB thermal profiling  in the lab ?

27. Is camera 'X' suitable for my intended task ? Alternatives ?

28. Is resolution really important ? and how much is enough ?

29. Can a microbolometer camera operate without the calibration shutter for video ?

29. Who can repair my thermal camera with 'X' fault ?

30. Can I repair my own thermal camera ? The challenges ?

31. Used thermal camera buying guide ? Model specific issues ?

32. Are dead pixels a fault and how do I get rid of them ?

33. Where to buy used thermal cameras & accessories ?

34. Thermal camera control software for old and new cameras ?

35. What is the history of thermal imaging cameras from beginning to present ?

36. What are the new developments in thermal camera technology ?

37. Modification of thermal cameras ?  What can be changed ?

38. What is a scanning thermal camera ?

39. Is a NIR camera capable of thermal imaging ?

40. Are attenuators available for thermal cameras to increase max temperature limit ?


Enjoy using your thermal cameras everyone.... they can be great fun 


Fraser

[Flanbix]

I am definitely interested on a topic about the optics involved in the thermal camera.
Decoding Focal range, FOV, F-number etc. for a particular type of sensor...

[cynfab]

Fraser,
I am interested in anything you choose to write on the subject of Thermal Imaging/Cameras.
You have forgotten more about this topic than I ever knew, and I envy your collection of hardware.
Thanks for all you have contributed.

[Fraser]

I might do a review of new cameras that I add to my collection such as the DRS Watchmaster ULTRA 6000 camera that is current technology, but I doubt I will be posting about the older cameras or technology any more.

The DRS camera is a pan & tilt 640 x 480 30fps platform with both IP and CCTV PELCO D control. Video streaming and conventional composite video output as well. Built in DVR and motion detection. Gorgeous bit of kit  The camera is also sold under the Ganz brand. Picture attached.

Fraser

[tautech]

I'm interested in simple use on PCB's, faultfinding use, design confirmation, power electronics and the like and maybe some light industrial, switchboards, motors etc.
From your list that I think these would cover most things for those of us with limited or no experience:

4. Help understanding Thermal imaging camera specifications. - the truth behind the 'marketing speak'.
14. What thermal cameras are best suited to specific tasks ? i.e. PCB inspection, Maritime roles, building surveys and wildlife observation.
15. Is buying  really cheap consumer grade thermal camera a false economy? why ?
26. How do you carry out PCB thermal profiling  in the lab ?
28. Is resolution really important ? and how much is enough ?

Thanks in advance.
Rob

[cdev]

I have no arguments with it being incredibly useful but the cost is too high for me to buy one. So I use LCD sheeting to do something similar when I need to know what is hotter on a PCB. It works well to identify hot spots, fast.

[PlainName]

Well this thread was visited 240 times since posting. It got six responses.

Don't be misled by this random-ish data. It can mean whatever you think you want it to mean. Instead of looking at 'only' six responses, why not appreciate the order of magnitude more visits?

Personally, I have no idea what I would like to see in a topic, so the question is right over my head. I am interested in this stuff, but until I see it I won't know that I am (I am  not an expert and don't know what I don't know). I dip into these threads and see what catches my attention, learn bits here and there.

If you were to post random thoughts I'm sure they would be relevant, interesting, and informative. They may get no comments (we could all be dumbstruck) but check the number of viewers to see if anyone is checking them out.

Slightly aside, I tend not to comment "Wow, that was super fantastic and enjoyable thanks" after every such post unless it is a one-off or similar. The reason is that pretty rapidly it gets to be expected and then any post that doesn't get a stream of those comments is seen as being very poor, regardless of what it is. You can't keep outdoing superlatives infinitely, in other words. Your problem is that every one of your posts deserves such comments

[Fraser]

Hi dunkemhigh,

Understood. It is not praise I seek, it is interest in what I post. If there is little true interest then I am wasting my time producing images and commentary. My X-Ray image thread was something I just did for fun and I just published what I would have been imaging anyway. It was popular !

Doing a teardown of a valuable thermal camera is both time consuming and can present a risk to the camera. Why produce such content if it is truly of little interest to forum members.

This post was started for a very specific reason. I was planning to do some more teardowns and reviews of my thermal cameras. That would have been a large investment of time and effort on my part. The 'test' was to see how much interest there truly was in thermal camera technology rather than just people buying a 'black box' and using it rather than being that interested in the inner workings, or more advanced topics within Thermography.

I see little in this thread to indicate that there are a large number of people on this forum interested in the inner workings of thermal cameras, lenses, correct usage or other useful information. You will note that I produced the FLIR E4 Useful Information Thread. I created it as a service to the forum as I knew it would be of interest to buyers of this popular camera. I sought no thanks or gratitude. If someone had offered to answer my thermal imaging questions a few years ago, I would have raced to take advantage of such a rare and valuable offer. Such a response is not evident here on this forum.

It makes no sense to me to create content of very limited interest or audience. That is just how I see things. I will always try to assist individuals with questions and problems. Only this week I was providing hopefully helpful comment to an i7 owner and a Indigo Alpha owner. They needed help. I provided such knowing that it might assist them. No reward is sought. A simple thanks is enough. That is just polite.

So be assured, I am not throwing a tantrum because few people made comments on this thread. I am just disappointed to see that my interest in all things Thermal imaging related is very much limited to a very few other forum members. That is life, it is common where specialist topics are concerned. That is why people come to me for help or to repair their cameras. I am currently in a minority. I had thought that the availability of cheaper thermal cameras might have resulted in more interest in the technology amongst forum members.

Finally, the visit count is pretty meaningless. Responses to a direct question indicate interest and a wish for the OP to know such.

I am happily repairing thermal cameras at the moment and have a brand new state of the art thermal camera arriving on Friday. I am not seeking more work or attention. I need to use my time where most appropriate. Posting teardowns and FAQ's etc has just dropped to the bottom of the priority list, that is all.

Time to get back to reassembling a gorgeous professional NEC AVIO TH9100 thermal camera now.

Thank you for your comments though. At least you took the time to write

Fraser

[PlainName]

I am currently in a minority. I had thought that the availability of cheaper thermal cameras might have resulted in more interest in the technology amongst forum members.

Yes, I would expect that too, but not for a while. It takes time to realise you need to know about emissivity, for instance, and then figure it might be an interesting topic to look into further. Meantime, the newer user may think "Ah! I remember something about that from Fraser's wotsit thread". At the time it would have gone straight over their head but now it means something and they might actually have a sensible question to ask! Much of this stuff seems to be 'learned' via osmosis

I appreciate that you spend a lot of time and resources doing this kind of thing, and I enjoy reading whatever you care to post. Perhaps one of the issues is that the tools are within hobby toolbox range now, but a realisation of what they can be used for isn't.

As an example of usage, I recently wanted to put some hooks into a ceiling to hang a wardrobe rail from. The trouble is, I don't know where the joists are and my using trick of making a small hole every half inch in a line until I hit one is very sepcifically banned for this ceiling. The plaster and lath thickness make a pipe detector useless too. So, my plan was to use the thermal imager to see where they are - there must surely be a difference in temperature, albeit small, where the joist stops the roof insulation from being effective. Unfortunately, it didn't work (possibly because the room is about 4C currently and the attic a bit warmer!) - absolutely flat so far as I could tell. I am moving on to using magnets but, again, the plaster thickness is proving troublesome...

[Fraser]

dunkemhigh,

Now you are talking my language.......

When passive thermography is not enough, turn to active thermography 

Active thermography is where you inject thermal energy into a surface and watch the differing rates of heating or cooling. A wall or ceiling may look pretty much 'flat' to a thermal camera due to low thermal gradient across its surface. If you inject heat into the wall with a halogen lamp or more likely a hair dryer or paint stripper air gun, the surface will heat up but areas of greater thickness will dissipate the heat faster than thinner areas. The joists will act a bit like a heatsink and draw the heat away from the plaster quicker than the plain plaster cools naturally.  You watch the surface as you heat it and as it cools. You should be able to see the screws, nails and joists as the thermal contrast in the surface is enhanced.

Another trick is to choose the time of day for such tests when thermal differential on each side of a surface is greatest like an air conditioned room in the morning as the sun starts to warm the other side of the wall. you can see the bricks and mortar with ease.

Creating thermal contrast in a relatively 'flat' thermal gradient target is just one of the challenges we face in thermography. Passive thermography is only half the story 

Hope these comments help 

Fraser

[Fraser]

Some active thermography reading for you ......

http://www.qualitymag.com/articles/91207-active-thermography-for-nondestructive-composites-testing

http://www6.cityu.edu.hk/seam/cndt.thermography.html

http://www.twi-global.com/technical-knowledge/published-papers/infrared-thermography-as-a-non-destructive-tool-for-materials-characterisation-and-assessment/

I personally recommend a 2KW paint stripper gun for active thermography of small areas. Large areas are better heated with an array of Halogen directional work lights.

Fraser

[in.Vitro]

1. What is the difference in image quality produced by Pyroelectric Vidicon, BST, PZT and Microbolometers ? A review of the different technologies

2. Cooled Vs uncooled cameras, what are the differences in terms of maintenance and image produced?



6. What sets a thermal cameras temperature measurement range capability ? Can it be increased ?

8. What is the operational life of a microbolometer and what dictates such ?

10. Can a 9fps thermal camera be upgraded to >9fps ? What are the implications of such ?#

12. Fire Fighting cameras, are they any good for electronics and other tasks ?

13. What are the names of the main manufacturers of thermal cameras in the world. i.e. not just rebadged brands ?

20. What are the different lens technologies and issues with such ?

21. How do you clean  thermal camera lens ?

23. Can a telephoto lens be added to a thermal camera ? How ?

24. What are the thermal camera industries dirty little secrets ?

28. Is resolution really important ? and how much is enough ?

29. Can a microbolometer camera operate without the calibration shutter for video ?


33. Where to buy used thermal cameras & accessories ?

35. What is the history of thermal imaging cameras from beginning to present ?

37. Modification of thermal cameras ?  What can be changed ?

39. Is a NIR camera capable of thermal imaging ?

40. Are attenuators available for thermal cameras to increase max temperature limit ?

[PlainName]

I personally recommend a 2KW paint stripper gun

Ah! Thanks for that info, Fraser. I will give this a whirl tomorrow, preferably without burning anything down. Very useful to know it can be done - that's  half the battle, I guess.

[PlainName]

I will give this a whirl tomorrow

An air gun of some description seemed to me not to be appropriate in this instance since the heating would be localised and inconsistent - would I be able to see the faint joist against the splotches of uneven heating? So, instead, I just put a fan heater in there and left it for an hour.

And it worked At least, I think it did - I  have  yet to make any holes, but the marks we made are in the right orientation and joist-distance apart.

This was using a TE Q1 set to minimum 2C range. A Flir Infracam (RRP 10x the TE when it was new) couldn't quite do the job - you can make out the joist if you know where it is, but not enough if you're trying to find it.

[Fraser]

Dunkemhigh,

The technique with a hot air gun is to move it in a raster fashion left to right and the up and down. A bit like when you spray paint something. Keep repeating that motion for around 1 minute or so.. The distance berween the surface and the hot air gun nozzle should be around 1 foot and keep the gun moving to avoid very hot spots.

The heat equalises across the surface and reveals the differing thermal masses. It is often as the area cools that you see the most detail. An area of around 2 feet by 2 feet is optimum but toy can go to 4 feet by 4 feet at a push with long sweeping arcs of the hot air gun.

Fraser

[PlainName]

I might give that technique a go, then, to confirm what we have. It struck me that the difficulty is in finding the approx area to start with, but now I know that I only need to paint a few inches square. Much more doable.

[0-8-15 User]

I would love to hear something about those two:

4. Help understanding Thermal imaging camera specifications. - the truth behind the 'marketing speak'.

16. What dictates the accuracy of measurements taken using a thermal camera ?

[Rico]

Hello, lurker here.

I see you were feeling discouraged from sharing your knowledge by an apparent lack of interest and thought that people were either disinterested or already familiar with thermal imaging technology.

I would like to assure you there's definitely a large number of people (like me) who will stumble in here for years to come, and who appreciate learning anything and everything you're willing to share.