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preparing for the thermal imaging leap


Chad Fabry

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I just started re-researching cams. Tell me what's important and what's not. If you have a specific model you want to endorse, I'm willing to listen.

I want to spend two hundred but I'll go as high as four grand- I don't want a bunch of stuff that's unnecessary for home inspection.

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I've had a 320x240 Fluke for several years. I obsessed so much about it at the time, I thought I had to have high rez; now, I'm not so sure. I think 160x120 is fine for building diagnostics.

You want interchangeable lenses, 2 batteries and a charger, and good general handling characteristics. If you get into whole building scanning, you need a wide angle; it's not just a want...you need it. Otherwise, it takes forever. A lightweight camera would be nice; it gets surprisingly heavy holding it out in front of you at the proper orientations for long periods of time, and if you're doing a lot of scans, it takes long periods of time.

I wouldn't own a battery powered tool that didn't have a couple batteries and a charger.

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I have a TIR, as well. Ben found ours at 2K off retail, which was nice. IR cameras are strange beasts. You can point one at an obvious problem and receive no confirmation at all. But ... they can also reveal issues you couldn't have known about otherwise.

I've founds tons of leaks after running water in a bathroom, and then scanning a drywall ceiling beneath the bathroom. You can also see chimney-flashing issues by scanning drywall beneath chimneys.

I've scanned tons of EIFS walls, but have never found confirmations of moisture. I don't know if that's a lack of understanding on my part, or if the EIFS is too thick.

IR cameras aren't magical, but they absolutely are helpful. Mine has 120 x 160 resolution, which isn't terrific, but 340 x 340 was 10K more when I bought the TIR.

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I agree on using IR for EIFS; I don't think it's necessary. Same thing with flat roofing; I wouldn't bother with IR for roofing.

The problems come from scheduling; if you're looking at stucco or roofing, you have to wait for the optimum conditions, which are often at strange times.

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I have what is considered a low end thermal imager- (Tis) It's far from perfect but very useful. I use it on every inspection. I have found many issues with it and include the thermal image in the report.

Just last week saw an unusual reading in radiant floor heat that I reported as a possible/probable leak in a slab. Sellers realtor made a big deal about my report(which I could care less about) They brought in a heating pro who called me to come back-sure enough leak was right were I said it was. Have also found radiant ceiling heat not functioning. (thankful I don't come across that crap to often!) Found active ice damming many times that you could not see without which moisture meter then conformed. Two weeks ago found missing insulation in older house that was totally rehabbed over zero clearance gas fireplace. (builder/seller actually called me and thanked me-imagine that) I could tell you many more times but I figure you will get the point.- even the cheap end Tis is very useful-(might be all you need) Below is a sample of a thermal image using the Tis

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201441594047_Radiant%20Heat.png

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John Callan

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Check out Milwaukee.

The M12 has 160 x 120 res.

A very good camera for a better price.

I find the 12 v lithium ion battery to be plenty good and it recharges literally in minutes.

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tn_2014414234342_flor.jpg

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The logo tag on every pic is annoying but that is the world we live in today. We're walking billboards.

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They're all pretty good now. If I was going to get one today, I'd go Fluke Ti100. It's really all one needs. Feels really good in the hand; ergonomic, light. No interchangeable lenses, but you probably don't care; doing full tilt whole building work (where you need a wide angle) is boring. About $2200-2500.

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You can do interiors with a standard lens if need be, but it's a whole lot easier with a wide angle, and the images you output for clients make a lot more sense to them. I don't know if there are cameras with less than 320x240 that have the wide angle lens option. You get much smoother .jpgs from a 320 camera. My Fluke is 4+ years old now and has always worked perfectly, and I've used it a lot, so it's paid for itself. I won't buy another until I have to, but it will be another 320 model, and it will cost a lot less than last time.

I've seen some remarkable images of wet EIFS but I think they're very hard to get and probably wouldn't rely on IR as a primary moisture detection tool. The one guy I know who does a lot of that has a Tramex meter for it.

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I think you're right. You got to get into high Rez to get interchangeable lenses.

So, you think hi Rez is that much better? I waffle, wondering if it really is. Not for building diagnostics anyway. Machinery for sure, but not buildings.

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I had a FLIR B40 at the day job. It was $5k when we got it, and it was a demo. Now you can get into 120 pixels for around $1800. They still use the same shitty batteries though, and you only get one.

If you are going to learn as you go then anything that fits your hand well in the $2-2500 range will be more than enough camera for HI work. There are probably a few in the $16-1800 range that are good enough. Try a few out before you buy, comfort and ease of use are at least as important as anything else mentioned.

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From FLIR:

MSX Thermal Image Enhancement

Numbering, labels and other key features aren?t always apparent in a regular thermal image, often requiring a separate photo for reference. Instead, MSX virtually etches those visual details onto the infrared image in real time to create an all-in-one, thermal picture that shows exactly where problems are heating up.

Essentially, it overlays the high contrast data from a visible spectrum image onto the IR image. Taking Scott's image with my Bcam at 8 degree limits I would barely see the bifold doors, I would need 18 degrees or more of range to pick up the individual louvers.

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Oh.

I guess that's a benefit of the high rez; my images all look better than that. They're so clear, I don't even need to do the Fusion thing; it's a very clear IR image.

So, the Flir technology provides the benefit of high rez without the cost.

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I agree about the Flir deal--in most cases a 320 camera will produce an image that's equal or better. If there is nothing with sharp edges in the image it can be a little soft, but part of the skill of using the thing is knowing what you're looking at and what it means. No doubt the Flir technology is a response to users who complained about difficulty focusing and interpreting their images, and/or showing them to the unwashed masses.

One of the Testo cameras has a routine where it takes two thermal images in very quick succession and somehow combines them for a sharper image. Samples I've seen have looked great.

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  • 1 month later...

I've taken a few photos of different cameras I've used/had my hands on. I use a T420 much of the time, but have an E series for a back up.

You can look at some images of various cameras here https://plus.google.com/u/0/b/117719861 ... 6547295169

When you click on a pic, you can then click on "photo details", to see what camera was used.

After using / having a few, I'd say a combination of resolution and sensitivity is king. For example, my first camera a E40BX had lower resolution than a B60, but pics were/are better and was no comparison in the field, and the E Series has same resolution as the T Series camera I have, but there's no comparison IMO.

The MSX is handy for panel scans, but I turn it off while scanning buildings myself..

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  • 4 months later...
  • 3 weeks later...

Nice discussion on thermal imagers. A couple of points and some nit-picky details you should all be aware of if using a thermal imager in your investigations.

The two most important considerations for thermal imagers are resolution and thermal sensitivity. In both cases the better, the easier the image will be to resolve the thermal patterns. But, in the cases of great temperature differences (think evaporating water, insulation anomalies when temperature difference is high) a cheap, low end, usually will provide a thermal pattern you can see. Nice looking image for your client, NOT! And you will miss many of the details of subtitle thermal patterns that provide inspectors clues to a possible issue.

If you plan on provided the image in your report to your client or utilize thermography as a primary tool for your investigations, a minimum resolution of 320x240 is a good idea. Thermal sensitivity is the other part of the equation and should be a minimum of 50mK. The better the sensitivity (lower value) the better the ability of the imager to see subtitle temperature differences and thus a better resolve of thermal patterns. This is especially true in the shoulder seasons when temperatures inside and out are similar.

Overlapping or merging visual images into the thermal can provide details that the low resolution cannot. I feel it a trade-off that maybe necessary when getting a cheap imager. It even allows you to see through glass ;-)

Testos super resolution is software manipulation, merging multiple images together, usually providing greater detail. I've used it on all Testo imagers that have it and find it does help create a sharper image (most of the time). Remember though, thermal sensitivity. If the imager cannot "see" it, no matter what you do you cannot make it appear like magic.

Of course, price point is a very important consideration. Don't go bankrupt on a purchase, but do consider the best (resolution and thermal sensitivity) your money can afford. For building investigations, I'm not sure why you would not use one. Though I've heard stories of the past when home inspectors did not use moisture meters, assuming it was a liability to use one.

Forget the iPhone add-on as a professional tool, though it would be nice to carry one at all times, just to have something in your back pocket to provide more information. We are not yet at the point to have quality thermography in smart phones.

Tim, excellent images. Let me put my BST (Building Science Thermography) hat on:

As a trained thermographer you should be aware of the following, though easy to forget they are important:

In most building applications, specific temperatures are rarely relevant. We look for thermal patterns to locate issues with a building we cannot see with our eyes. Those pattern specific temperatures will vary considerable, hour by hour, and are usually of little import. One important temperature contribution for building investigations is dew point. In this case temperatures below dew point are important and useful to investigate further when observed. And forget using numbers to calculate heat loss. It is a difficult science to correctly interpret temperatures to assign an energy loss value. Though it can provide details of where energy loss is occurring and with a lot of work some SWAG to the amount of loss.

I notice you provide a spot temperature on all your images. Though some of the lower end imagers do not have the ability to remove that spot, it can usually be removed later when post processing. Because post processing can eat up bunches of office time, I rarely see the spot removed when these imagers are used for reports. However, when the spot can be removed pre-imaging, you should do so unless you find it provides relevant data within the image. If you use temperature data, adjusting for correct parameter settings are required for correct temperatures values. Even I rarely tweak with the parameter settings onsite, instead entering the information later from the data that was collected during the site visit, but only if necessary when I need to include temperatures.

In some of your images the tilde symbol "~" is present. This indicates the imager has not had time to equalize its temperature or come to a constant temperature. It requires a Non-uniformity correction (NUC) and the tilde symbol warns you the temperature measurements are not accurate!

Bottom line, thermography is a great tool. In most cases it's very easy to operate and the costs (and quality in some cases) are coming down so anyone can buy one and easily save an image. Inappropriate use can lead to unresolved issues or misinterpretations. Proper training is critical to successful operation and your future as a professional.

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