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#1
08-07-2009, 04:22 AM
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Anyone use a laser thermometer?
I've been looking at using one of those non-contact Digital Infrared Thermometers for detecting ore bodies and was wondering if anyone has ever used one? The 30:1 units are in the low $100USD range so much cheaper than a Thermal Imaging Camera and might even be useful for treasure hunting in the fall or spring when there's a larger temperature variation between day and evenings which would be the time to take readings.
What say ye? Randy 
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#3
08-07-2009, 07:29 AM
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I tried one of them and posted my test results here: http://www.geotech1.com/forums/showthread.php?p=52102 I only tested during the late spring at the beach. What I didn't post is my testing inland, where I found that wet or damp soil gives much colder readings than average, and shaded areas are much colder than sunlit areas of the soil. All this surface heating by the sun seems to cause the most significant temperature variations that can be read from an infrared thermometer. The idea of using one of these thermometers to locate buried metals seems a very poor idea to me, after a day of experimenting. In order to be successful, I would expect you need to search a flat area with no noticeable shadows shortly after sunrise or sunset. Then the problem becomes one of range. a 30:1 thermometer does not have a very good range because it is averaging a lot of noise within that cone that I would expect to miss all but the largest treasures that are in close range, and buried near the surface of a place that does not have any significant shadows. In theory, this method seems like it would work, but after trying it, I figured I could cover more area with a metal detector, which has greater depth, similar range (6-ft), and does not get false signals from shadows. About these thermometers.... They work good for taking the temperature of something that you do not want to disturb, such as rotating machinery, the side of a building at close range, the surface of a wall, etc. I use one of these as a preliminary indicator to tell if there are signs of moisture behind a wall. I never use it to search for where moisture is in a wall, I only use it to check the places where I suspect moisture before taking out the thermal imaging cameras. What the thermal imaging cameras show is vastly superior to the readings you can get with these thermometers. You see a picture that looks like a photograph of the temperatures. The difference between using a thermal imaging camera and an infrared thermometer to search for buried treasure is similar to the difference between using a camera and a light-meter to search for a treasure on the surface of the ground (where the light meter is equivalent to a calibrated one pixel camera with a 30:1 cone of view). Think about it.... If you had to wear blinders that prevent you from seeing the ground, which would you rather use to find a treasure on the surface? ... The screen of a camera, or the face of a light meter? This is basically what you are doing with infrared huntting during the best conditions. If you wanted to find treasure from infrared, a digital imaging camera would be your only hope, in my opinion. And that hope would depend on how deep the treasure is buried, as well as the composition of the soil and quality of sunshine. Moisture in the soil will play a very large part in this. Best wishes, J_P
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#4
08-07-2009, 09:36 AM
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the thermometer idea I think will not work, unless a very big object is under few depth of flat soil... possibly sand, I see it better than humid soil... as described by JP. I see also just thermal camera, even low resolution, as unique possibility in thermal scan for objects buried. But the problem, as always, is soil... gradient attenuation due to water trapped in the soil is a real pain in the *** I think at interesting depth. Also, I think maybe a cooled (very hard cooled, say liquid nitrogen stuff...) is required to achieve required accurancy and resolution in small thermal variations due to targets. I don't belive semiconductor stuff can produce accurate results at room/normal temperature. If so... the camera will be heavy... and whole system will costs a lot... considering you've to spend also for liquid nitrogen stuff... and not easy to operate I think. Kind regards, Max
__________________
"Kill for gain or shoot to maim... But we dont need a reason " someone said...
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#5
08-07-2009, 11:32 AM
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The Flir BCAM SD is a popular model that costs $3450 and weighs 1.21 lbs, with a resolution of 0.1 C, and could be used for the purposes we are talking. These thermal imaging cameras can also be rented for 3 days in the $300-500 range. I still doubt you will find much treasure unless it is large and near the surface, with optimum soil and sunlight conditions. Best wishes, J_P
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#6
08-07-2009, 11:45 AM
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There's one person in Brazil who has one from local Knouzm dealer and according to what I heard, with good results. I don't have his contact, so I can't speak further about this. In my view, if the mod includes a redesign of the sensor with data gathered on a particular wavelength, it can work. Usually, early evenings are the best time as the buried object will have a different temp gradient.
__________________
"Should exist injustice and untruths towards working LRLs, I'll show up to debunker the big mouths"
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#7
08-07-2009, 03:01 PM
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Randy, Check with Tim Williams (LRLMAN.COM). He has used one with his Arc Geo data logger. I don't have the details, but sounds like it works.
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#8
11-24-2009, 10:56 AM
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About thermal imagers
Hello everybody,
This is my first post though i've been looking this site for a very long time. I am a level 3 professional thermographer and i can assure you that thermography and laser thermometers have no use in finding burried objects. Thermal imagers are only capable of measuring the infrared radiation (temperature depented) from the outer "skin" molecules, thats why when we measure a bearing protected with a cup in contact with it we assume that the bearing is at least 10 degrees celcius hotter than the cup. Although i was sure about this i made some tests with my camera (50000€ price) with metal plates burried at depths from 10 to 30 cm and i saw nothing worth mentioning. And i tried with every possible configuration (emmisivity, temperature windows etc).Anyway if someone is still interested in learning more about thermal imagers i would like to help.
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#9
11-25-2009, 09:52 AM
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Thank you for professional insight.  The majority of Geotech members (with some notable exceptions  ) are already convinced that the use of laser thermometers to find buried treasure is complete nonsense. However, a select few are insisting on flogging a dead horse.It would be very interesting if you could post some images of your experiments with the buried metal plates.
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#11
11-26-2009, 01:43 PM
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airman, I don't know what kind of soil you have, but I can only assume there is a big difference from place to place. I certainly don't claim to have knowledge on using IR for treasure hunting, but some people do claim it can work. Maybe you should talk to someone with actual treasure hunting experience first. Could be you are overlooking something.
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#12
11-26-2009, 04:47 PM
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still not convinced ?
People told you for years now... and still think you can see through walls and soil ??? Like superman !?  Super-*****-hole! 
__________________
"Kill for gain or shoot to maim... But we dont need a reason " someone said...
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#13
11-26-2009, 05:10 PM
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Hi Mike(mont),
as i said at my previous post thermography can only measure the "skin" molecules emmited infrared radiation. This is a foundamental principle of thermal imaging and it is not said by me but from all the thermal imaging experts. Believe me i would be very happy if i could find treasures with my equipment and i wouldnt have to buy and construct metal detectors.When i have the time i'll post some articles of well known thermal imaging experts explaining what i'm saying. And i trust those experts and my experience much more than i trust some guy saying that he's heard something about a guy who found something with a "magic" thermal imager or laser thermometer. In some cases you can detect something buried but the temperature difference between the object and the surface has to so big that it is impossible to happen at normal conditions. For example we can detect a heating pipe inside a wall but the pipes temperature is about 80-90 degrees celcius and the wall is at about 25-30 degrees celcius.
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#14
11-26-2009, 05:20 PM
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Well I know for a fact that NASA uses it. I guess all I'm saying is if you have such nice equipment it might be worth looking into it further.
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#16
11-26-2009, 06:57 PM
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My BS alarm won't shut off.
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#17
11-26-2009, 07:56 PM
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NASA is not using technology that's 10-20 years ahead of what's commercially available. If anything, it's 10-20 years behind. I was a shuttle engineer at NASA-KSC in 1987 and was surprised at how old the technology was... a lot was from Gemini & Apollo projects. This is sometimes a necessity for them, as they need 100% guaranteed reliability. This is not to say that their R&D labs aren't working on cutting-edge technology, but that's not what they're currently using.
Mike, I wonder what you disagree with airman21 on? I know laser thermometers have been marketed for treasure hunting, but I don't know of any treasure recovery due to one. One of the often-touted claims of IR proponents is the concept that buried treasure has a longer thermal time constant than the surrounding soil, and therefore creates a hot-spot late in the day. If anything, metal has a faster thermal time constant, and would be invisible to IR sensors when buried. Do you agree or disagree? - Carl
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#18
11-26-2009, 08:10 PM
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I also work with thermal imaging cameras. And I agree with airman21. I found these cameras are good for seeing framing behind a wall, or moisture in a wall, and for looking or thermal leaks in a building. They also can show the temperature gradients on the surface of nearly anything you take an image of. But these are still a little crude compared to what Nasa uses, and they are expensive compared to a professional digital camera. I have never seen anything in the landscape outside a building that led me to buried treasure, buried pipes, or anything else buried except cold areas from wet spots and shadows. I can usually see where a parked car recently left it's parking space for a while, but no signs of things that I know are buried under the ground. But Randy's original question was not about the expensive thermal imaging camera. He asked about a cheap infrared thermometer. This is the same as using a light meter instead of a regular camera, except we are using a meter that measures infrared level instead of light level. Can you imagine that using a light meter would have anywhere near the image quality as looking into the back of a digital camera to try to identify what you detected? For example: A digital camera may take a photo of a house with some trees that have shadows under them. You will be able to see the entire image of the house as well as all the details of the trees and shadows and other things. But using only the light meter, you will only know there are dark areas and light areas as the meter is moved around. You will have no clue whether you found some bright shiny gold or a reflection from a trash can or maybe a light bulb. It is the same with thermal imaging. Can taking temperature readings all over the place similar to using a light meter a light reading survey work to identify your target? What fool would try to locate treasure with an infrared thermometer? One who believed advertising propaganda that says it has a cave detector built into it? Wouldn't a serious treasure hunter insist on a thermal imaging camera? And wouldn't he quickly learn that not even a thermal imaging camera finds the treasure? Maybe I am wrong... So let's see all the treasures recovered using an infrared thermometer or thermal imaging cameras. Best wishes, J_P
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#20
11-27-2009, 03:48 AM
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More bait and switch. This thread started out with laser thermometers of which I said Tim has used one with his data logger. Then the thread shifted to airman and his 50,000 pounds IR camera--NOT THE LASER THERMOMETER. Things went downhill from there (as usual).
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#21
11-27-2009, 04:44 AM
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#23
11-27-2009, 01:45 PM
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I am not an expert with the use of laser thermometers, or IR cameras. However, just yesterday at a T-day dinner I had the opportunity to converse with a user of such technology. He uses these things in his daily work and has gone to school to learn how to use them.
 Upon questioning him, about the uses and applications for laser thermometers, etc.; he confirmed everything that airman21 and Carl have described about the fallacy of using such instrumentation for locating buried metals or treasure. If Tim Williams used it alongside his logger gadget, it only goes to show that those among us who want to mis-apply certain technology, are adding nothing to the location solution, but are merely confirming their own ignorance. 
__________________
 The Wallet-Miner's Creed Why bother with the truth, when it doesn't suit the argument?
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#24
11-27-2009, 02:14 PM
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The problem with this approach is we have a much better tool .. the thermal imaging camera that will make an image better than a crude temperature map, while showing finer resolution temperature gradients, and will even show objects on the ground to help identify where the warm/cold spots are. So there is no need for wasting time making geo-log surveys when you can quickly take a snapshot in many directions from one location. And the fatal problem is the better thermal image does not show you where buried treasure is. Using a geo-logger with a thermal imaging camera is kind of like the idea of using an ordinary digital camera with a geologger. Why make a goelog map of bright and dark spots on the surface in several colors when you can simply snap a picture and get the job done without the trouble of a survey? The photo you take will be much more useful for showing what you found and give a lot more detail. But unless the treasure is at the surface of the ground where it can be seen, I doubt you will find it with a digital camera. The thermal imaging camera doesn't do much more. It only improves the photo by showing temperature gradients on the things you see on the surface, while giving a poorer resolution photo. I imagine that a very few treasures could be found with a thermal imaging camera. For example, if a corroded coin was lying on the surface of the ground, and the temperature of the air was changing rapidly as the sun began shining after a dark cold period, you may see the coin as a spot that showed a different temperature than the surrounding soil for awhile. This could help for finding tarnished bronze coins that are hard to see lying on the ground. I think I will pass on that idea. Any $200 metal detector would also find the same coin without fussing with a thermal imaging camera to find it. I would still like to see all the alleged buried treasures that have been recovered using a digital thermometer. Best wishes, J_P
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#25
11-27-2009, 02:41 PM
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 I think this falls in the category of; if the only tool you have is a hammer, everything begins to look like a nail.
__________________
The Wallet-Miner's Creed Why bother with the truth, when it doesn't suit the argument?
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