Where to buy a cheap FLIR or make one?

[Mr RB]

Hi guys, I have a need for a FLIR (forward looking infra red) camera, the ones that see body heat in the dark and can be pointed at a PCB etc and show the heat of every component by how bright it appears on the camera.

I don't want to spend more than about $250 and commercial ones seem to be in the thousands.

They are pretty easy to make, I remember seeing some build threads a few years back where all they did was cool a cheap CCD monochrome camera to -X degrees C and it becomes sensitive to infrared light instead of visible light.

Does anyone have any suggestions? Ie; where to buy one cheap or an easy way to build one?

I have some 40W peltiers that will do -10'C maybe even -20'C if set up right and I probably have some monochrome CCDs in the junkbox, and closed loop temp controllers etc won't be a problem.

All input is greatly appreciated!

 

[ericgibbs]

hi,
I saw a web video some time ago that used a PC mono camera, apparently most camera's of this type have an in built IR filter, which the video showed how to remove the filter and convert it to IR.

EDIT:
https://www.google.com/search?q=hac...t&rls=com.yahoo:en-GB:official&client=firefox

https://www.youtube.com/watch?v=z-ShrNzR-4c

 

[Mosaic]

Take your pick.

Amazon.com: ir security cameras

 

[crutschow]

Unfortunately all IR is not the same. The hitch is that IR covers a wide range of wavelengths. The IR sensitivity of a CCD, even when cooled, is in the near IR (perhaps 1 micron or 1000nm wavelength), close to the visible spectrum. Hot objects near room temperature put out very little radiation in that wavelength, instead it is concentrated in the far IR region (≈7 to 14 micron wavelength) which is where FLIR cameras operate. (Look at a graph of black body radiation around 300K room temperature for further understanding of this.) This requires special sensors (typically bolometer sensors for commercial IR cameras). These sensors are a low production device and thus expensive, which is why FLIR imagers are much more expensive than CCD imagers.

 

[Dr_Doggy]

To put it in to perspective, all you really need is a thermometer and a lens to focus the HEAT IMAGE on to the temp probe.

the $$ comes in since you need 600 X 800 number of probes to get 600 X 800 resolution, and fitting that in to a sqCM isn't easy, even for the pros (plus cooling)

The best DIYer iv seen do this was a guy who had only a few sensors hooked vertically and then did progressive horizontal scans with a stepper, but he still had a really low resolution and long scan time......

 

[Mr RB]

Eric and Mosaic- Those IR camera hacks juts make the camera able to see near IR, which most CCD will do fine. For example my Canon stills camera can take a photo of my infrared remote control lighting up bright.

What I'm after is FLIR, which is achieved by cooling the CCD below 0 degrees C which makes it sensitive to body heat wavelengths.

Crutschow, thanks for the info, I knew that but was hoping for the link or someone who had done a FLIR mod with a peltier. I remember seeing some simply DIY builds a few years back, maybe they have been "removed" from the net, as google searches now don't seem to find anything.

 

[crutschow]

What I'm after is FLIR, which is achieved by cooling the CCD below 0 degrees C which makes it sensitive to body heat wavelengths.

Cooling a CCD will reduce its dark current and make it more sensitive to the frequencies it detects. But it will not make it significantly more sensitive to the longer wavelengths that an object near body temperature emits. The maximum wavelength that a normal Si CCD will detect, at any temperature, is about 1.1 microns, which is well below what you need.

You can not make a FLIR by cooling a standard CCD. There is no magic for that. If there was, Fluke and others would be using that for their thermal imagers rather than using expensive bolometer detectors.

 

[Sceadwian]

Mr RB, rent one, any decent industrial rental supply place should carry them.

 

[Mr RB]

Crutschow-

Cooling a CCD will reduce its dark current and make it more sensitive to the frequencies it detects. But it will not make it significantly more sensitive to the longer wavelengths that an object near body temperature emits. The maximum wavelength that a normal Si CCD will detect, at any temperature, is about 1.1 microns, which is well below what you need.

You can not make a FLIR by cooling a standard CCD. There is no magic for that. If there was, Fluke and others would be using that for their thermal imagers rather than using expensive bolometer detectors.

I don't believe you are right. As far as I know many of the high end military etc systems using high res cameras still use crygenically cooled cameras. There are plenty of references.

The big push to bolometer systems was for cost and small size, as it allows a similar result without the size, expense and power usage of multi watt crygenic cooling.

It's a shame the guys that I remember about 10 years back did it with some success at a hobby level using peltiers seem to be hard or impossible to find.

Scaedwian, thanks for the suggestion to rent one. I had not thought of that. I'd still like to have a play and see what can be accomplished as a hobby level project, when I get some time.

 

[Sceadwian]

Cooling an element will reduce its dark current and make it more sensitive to the frequencies it detects.
This is fact, but only allows for a higher sensitivity, it will not stretch the bandwidth the sensor/material will detect.

If you're having a hard time finding peltiers you need to be banned from the Internet immediatlty.

 

[audioguru]

Years ago, SONY got into trouble when their inexpensive video tape cameras could see IR heat though clothing and see "naughty things".
So they added an IR filter.
The new lenses in my eyes which were provided by cataracts surgery allow me to see "naughty things" in the dark. The lunar eclipse last night looked weird.

 

[crutschow]

Crutschow-

I don't believe you are right. As far as I know many of the high end military etc systems using high res cameras still use crygenically cooled cameras. There are plenty of references.

I wasn't arguing that some IR detectors aren't cooled, just that a cooled silicon detector is not sensitive in the mid or far IR region, where FLIRs operate.

I've worked on the design of a couple of FLIR systems for the military. The detectors are not standard silicon such as used in a visible light camera. They use detector materials such as Indium Antimonide (InSb) or Mercury Cadmium Telluride (MCT), which are sensitive to the longer IR wavelengths when cooled. If you read some of those references, you might have determined that.