Make - IR thermal imaging cameras

Make - IR thermal imaging cameras: "Makers and Making: IR thermal imaging cameras

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c0redump
May 15th 2007
I've been reading the IET journal article on infra-red thermal imaging cameras, and their medical applications. It mentions that a thermal imaging camera costs about £20,000 (about $40,000?)! Now, my question is this: why so expensive? Is it something to do woth the low volume of sales? Or is there some part or parts that really puts the price up?

Way back in the 1970s, I saw a thermal imaging camera that could show variations in body temperature. It showed my glasses (actual glass lenses back then) as black, opaque to IR. The lens in the camera was made of germanium -- yes, a shiny metal lens! Is that the reason for the high cost? Do modern IR cameras still have germanium lenses?

Hope somebody who's more familiar with IR cameras can answer this! Would be great to make a thermal imager, but it looks like a tricky problem if glass lenses can't be used.

John Honniball
Myself248
May 15th 2007
The microbolometer in a thermal camera is incredibly difficult to manufacture, but not $40,000 difficult. The trick is that since they're seen as high-end devices, any sensors with flaws are discarded, instead of built into cheap cameras. If they were a consumer-grade item, more defects would be acceptable and manufacturing would get cheaper. It's a chicken-and-egg problem.

Anyway, prices are coming down, you can get a very nice thermal camera for $5,000 or so now. Do some research, if you come up with a DIY method I'd be interested!
cajunfj40
May 16th 2007
Hello c0redump,

Myself248 is essentially correct regarding high-cost medical thermal imaging cameras. Low volumes, no defect tolerance, very high quantities of FDA red tape to qualify the device, insurance against lawsuits if it fails to see something, etc. all lead up to a very high end-user price.

What is your application? If you just want to see 'hot spots' and don't need the 'false color' image, you can take the IR filter off of a B&W video camera and 'see' IR. Google IR and B&W camera and you'll find oodles of links. Some camera sensors are more sensitive in the IR range than others, so look around to see what others have played with and had good results with. You may even be able to find a filter that blocks everything except IR, which would effectively increase the sensitivity of the sensor - it won't be blinded by bright lights, just the IR portion of that light. To do a quick check to see if a camera can see IR, flash a remote control into the lens while you watch the monitor output. If you can see the flash, the sensor can see IR.

If you're looking at medical applications, that's a whole other ballgame. I work in R&D designing cardio and neuro stimulation leads and adapters, and the amount of testing and red tape we need to present a case to the FDA that our device is 1) safe, 2) effective 3) better than the currently available stuff is quite expensive. I've got a lead design sitting in a tester that's over 270 million flex cycles, and it has to reach 400 million before it is acceptable. at 15hz, that's over a year of continuous testing. The tester, a Bose Enduratec (and you thought they just built speakers!) was not cheap, and our time to administer the test is not cheap either.

If you want a case study for why the medical products industry is and should be paranoid about testing, and why we charge so much (because that testing is expensive) Google the Therac-25. A software fault caused at least 6 known extreme overdoses of radiation therapy. A thermal imaging camera isn't in the same class - it does not emit stuff at the patient - but the idea is the same, in that if it harms or fails to detect harm to a patient the manufacturer may be held liable.

Have fun!
-cajun
HiroProtagonist
May 16th 2007
cajunfj40 sez: 'If you just want to see 'hot spots' and don't need the 'false color' image, you can take the IR filter off of a B&W video camera and 'see' IR. Google IR and B&W camera and you'll find oodles of links.'

This won't help the original poster if he's truly looking for IR thermal. Thermal imaging uses long wave IR. Normal camera sensors are sensitive to short wave IR, but this won't show thermal 'hot spots'.

c0redump: I saw an article on the web a while ago about a guy who made his own thermal imaging camera for under $100. He used the polymer sensors from PIR detectors - it was *very* low-res though. Unfortunately I couldn't find the article with a quick google, but it may still be out there.
machinemaker
May 17th 2007
Not sure if this helps, but I used to use a thermal imaging camera for trouble shooting industrial wiring. It was a camera made by Fluke the same folks that make multimeters. It worked great for finding loose connections, bad breakers, failing components. When you took images of people you could see quite a bit of difference in surface temperatures and it was a couple grand. However, Fluke products are a bit pricey and it had software for comparing images etc. I have to believe that one could build it cheaper.
Mysterio101
Oct 13th 2008
You can make a simple thermal imaging camera with $50 or maybe even less. it doesn't have an LCD though, it's kinda like a 'mechanical TV'. I'll tell you more later.

Bye all!
c0redump
Nov 30th 2008
@Mysterio101: yes, please do tell us more about this technique!
alankilian
Nov 30th 2008
One of the guys in the Twin Cities Robotics Group (tcrobots.org) works on
the Fluke IR cameras. They are down to $4,500 now according to this page:
http://www.transcat.com/catalog/productdetail.aspx?itemnum=98589TE

Sometimes he bring a test camera to a meeting, and it's great fun drawing
words on the wall with your finger and seeing them with the camera.
Huisjen
Dec 8th 2008
I'm getting into the home energy auditing business. I just bought a Flir/Extech i5 camera for the job. Its about $3000. It has an 80x80 pixel array, which isn't super high resolution, but is good enough to see the swath of cold left by air leaking around doors, windows, and sill plates.
wbeaty
Dec 15th 2008 edited
The lens would be the expensive part!

Hundred-pixel thermal camera $10:
http://web.archive.org/web/20070203225204/http://users.bestweb.net/~hobbs/footprints/fpspie11.pdf

Phil Hobbs' project uses ferroelectric/pyroelectric polyvinylidene PDVF film, the same sensor in IR motion burglar alarms and security floodlights.. To avoid buying 1000 gigohm resistors and to improve diode muxed switching, he uses light-biased red LEDs as the diodes.

Note that pyro plastic film only responds to temperature *changes.* Either it only can see moving sources (a thermal 'frog's eye' effect,) or the camera needs a rotating chopper wheel.

I don't think he mentions the lens. Pinhole? Polyethelene fresnel lens? Telescope mirror?
cashsale
Dec 17th 2008
Seems like something useful could be created with a single pixel of IR-sensitive material and a mechanical mirror/voice-coil scanning arrangement. Sensitivity would be horrible, but a tripod might allow one to produce a fairly high resolution image given enough time - seconds, minutes?. There would be some averaging as a result of the exposure time.

Yet another idea not suitable for the original poster, but a thought nonetheless.
MarissaLamb
Feb 2nd 2009 edited
The price of the technology has come down a ton. We are an HVAC company and shopped several cameras in the FLIR line. Overall we liked the FLIR B200 and FLIR B250 the best but also considered the FLIR B40 FLIR B50 and FLIR B60.

Ultimately we liked the ability to add aditional lenses with the B250 even though the B60 had a higher pixel count.
jschuch
Feb 6th 2009
If I were going to tackle this, I'd start with one of the inexpensive IR Thermometers that Harbor Freight is selling. Figure out how to get a signal out of the thing, maybe put a pinhole over the sensor to tighten up the dot size, and then build some sort of mechanical scanner. The scan speed would depend on the responsiveness of the sensor.

Would be a fun project.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96451

John
chaz_p
Aug 1st 2009
what do people think to these are they the correct lens or am going down the wrong route?

http://www.rapidonline.com/Electronic-Components/Sensors/Thermal-Sensors/TPA81-Thermopile-array-sensor/77927/kw/78-0792?source=googleps&utm_source=googleps
i really want a thermal imager to hunt with but dont want to pay thousands
ttgrthomas
Aug 4th 2009
One rotor simple-radio-controlled or telemetry-controlled helicopters are commercially available.
These Search & Rescue and Security helicopters usually are equipped with a very good digital camera.
Sadly though, far fewer UAV helicopters currently have IR Infra-red heat imaging cameras onboard.

[ quote from a recent makezine commentator ] -
'The trick is that since they're seen as high-end devices, any sensors with flaws are discarded, instead of built into cheap cameras. If they were a consumer-grade item, more defects would be acceptable and manufacturing would get cheaper. It's a chicken-and-egg problem.
Anyway, prices are coming down, you can get a very nice thermal camera for $5,000 or so now. Do some research, if you come up with a DIY method I'd be interested!' [ End Quote ]

So, on that note [ immediately above ], why not design, build and offer for sale very reliable, foolproof radio or telemetry operated **** one rotor UAV camera helicopters **** for Search & Rescue and Security purposes?
I cannot yet find any Extended Range versions with a fuel cell and compressed, metal-hydride or liquid hydrogen options that are for sale to us technologically hampered civilians.

Once done, you'll sell many THOUSANDS worldwide. Afterwards, maybe then you'll have enough of a customer base so that you can contact all your clients
& offer a ' consumer ' quality version of the IR Infra-red heat imaging camera .... for Search & Rescue and Security use.

Remember, limited range [ paltry poor flight duration ] is currently the main limiting factor in [ common civilian ] UAV Camera Drone technology today.

Doesn't have to be that way though .......

Me, I want one UAV at ' elevation ' immediately above me with a telemetry operated telephoto lense onboard it that's pointed at the other Extended Range UAV Helicopter up to 10 miles downrange. This way, a constant 'line of sight '
is maintained between the UAV hovering almost immediately above me and the one that's out there up to 10 miles radius from my vehicle.

With this very interesting strategy, I'm guessing that I'm technically ' legal ' with current FCC rules on using unpermitted Unmanned Aerial Vehicles. Right? The rule says that a ' line of sight ' must be maintained at all times.

Any questions? Find a very rare copy of 'Electric Car' magazine from 1995. Alan Cocconi at AC Propulsion in San Dimas, California was featured in this low-circulation ' market test ' magazine about electric vehicles. Call www.acpropulsion.com . Read all about the ' So Long ' UAV and Alan's experience with UAV camera drones in the 1980's & 1990's.

While you're at it, pick up a 248 [ maximum ] horsepower Electric Vehicle Motor with the necessary PWM / MOSFET power control electronics. Price? A mere $27,000. Best of the best for sure!

This powerful electric vehicle motor is currently installed in the www.acpropulsion.com T-Zero sports car and the new Tesla electric sports car at www.telsamotors.com

Bring me onboard in your company if I can spill any more profitable beans.

Employment is very scarce for those with less than a proper 4-year degree right now ....

480.528. 0 6 3 2, Mr. Thomas

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