Thermal Imaging Detector

[VictorPS]

I found the Thermal Imaging Detector at
**broken link removed**

1. Anybody has expereince with this detector?
2. What is the sensor inside?
3. Is it a camera?
4. Is it possible for us to DIY one?

 

[dknguyen]

Yes, it's a camera.

Can you build your own video camera? If not, you certainly won't be able to build a thermal imager which is the same thing, but harder in design aand with harder to find components (already hard to find for a DIY video camera).

So basically, no you can't DIY (they cost $10,000 for a reason).

BUT, those images you provided look more like an infrared camera to me...notice how you can see the plaid pattern on the guy's shirt? Thermal imagers can't see stuff like that...only temperature. Infrared cameras can. Infrared would also make more sense since that does not look like a $10,000 device.

Do you mean infrared or thermal camera? There is a difference (infrared being a low-light, night vision type camera that gives normal-looking black and white images. Thermal imager being the cameras that give you vision like from the movie Predator, with red, blue, black, white, and other colours based on heat intensity.).

Thermal cameras use a CCD-type element just like digital cameras, except these are responsive to very low energy, very long wavelengths (radiated heat). More sensitive systems require cryogenic cooling so they can be more sensitive because thermal noise in the circuits can be high enough to destroy the equipment's ability to pick up the low signal levels of thermal radiation.

Either way, you probably can't build your own video camera, infrared or thermal. Just get a regular low-light security designed for infrared and use a infrared filter to filter out visible light to get only infrared images.

 

[VictorPS]

Thanks for reply, I am clear now.

 

[AllVol]

I doubt the detector depicted at the website is a camera, the photo shown being only for illustrative purposes. The description clearly states the device is thermal, and as Dk states, visual detail could not be seen.

 

[panic mode]

imagin will be difficult but there is always a way...

 

[panic mode]

what are you trying to do? imaging? in not you can
try infrared thermocouple which is good for single point

 

[dknguyen]

I doubt the detector depicted at the website is a camera, the photo shown being only for illustrative purposes. The description clearly states the device is thermal, and as Dk states, visual detail could not be seen.

Hmm, yeah the more I look at the image the more I think that the photo is just for illustrative purposes. That would make sense if it really was thermal because then all you would see are those oval heat spot things in the image instead of the people's shoes and shirts and everything.

It could be using thermopile arrays. These are different from the pyro-electric arrays used as motion detectors in security detectors which can only detect changes in heat. The thermopile array can measure static temperature. Here is a device that uses a 8x1 thermopile array that is just sensitive enough to pick a out a candle:
**broken link removed**
To get an image of heat spots, you need many many more.

I wouldn't call it thermal imaging...since it's not nearly as accurate or as sensitiveas real thermal imagers, but it should work to pick up heat spots (if they are hotter than ambient by enough), but it's a lot cheaper (but still expensive, just possibly within the limitations of individual expenses). Here is a supplier of things like 32x32 arrays that are sensitive enough to pick out body temperature:
**broken link removed**
**broken link removed**

 

[ghoghnus]

hello dear user i want to build the infrared camera for termography can you help me about the componet that convert the photon of the infrared (that send from the body or other refrence of the heat) to image or pixel whats the name and data sheet ? tnx alot for help me.
excusme if bad explain becuse i'am persin and don't know english very well plase help me.

 

[philba]

actually, most digital camera sensors respond to IR. Most have an IR filter. If you removed that and replaced it with a filter that passed IR but not visible light, you would get bright spots where there is IR.

now, the reason the thermal imaging detector is expensive is more likely due to the fact that it does some image processing. the text says it can detect into and out of the detect area and maintain counts.

 

[dknguyen]

actually, most digital camera sensors respond to IR. Most have an IR filter. If you removed that and replaced it with a filter that passed IR but not visible light, you would get bright spots where there is IR.

now, the reason the thermal imaging detector is expensive is more likely due to the fact that it does some image processing. the text says it can detect into and out of the detect area and maintain counts.

IR and thermal imaging are different. They are at different wavelengths and the thermal imaging is more expensive because the wavelength carries much less energy with it than the IR (or something like that).

 

[philba]

have you ever seen an image where the IR filter has been removed? you can definitely see there is an effect.

I believe that thermal imaging is in the 900 to 1400 nM range which is definitely in the range of the cameras. Certainly they respond to 950 even with the filter in place.

 

[dknguyen]

I think a distinction should be made between near-IR and far-IR imaging, where near-IR is usually referred to as just IR and is what visible light cameras are sensitive too, while far-IR imaging is what is usually refered to as thermal imaging.

**broken link removed**
https://electronics.howstuffworks.com/nightvision.htm

 

[Hero999]

Wikipedia has an interesting article on infrared.
https://en.wikipedia.org/wiki/Infrared

Even more interesting is Terahertz radiation.
https://en.wikipedia.org/wiki/Terahertz_radiation

Because of terahertz radiation's ability to penetrate fabrics and plastics it can be used in surveillance, such as security screening, to uncover concealed weapons on a person, remotely. This is of particular interest because many materials of interest, such as plastic explosives, exhibit unique spectral fingerprints in the terahertz range. This offers the possibility of combining spectral identification with imaging. Some controversy surrounds the use of terahertz scanners for routine security checks due to the potential capability to produce detailed images of a subject's body through clothing.

Wow so those "x-ray" specs allowing to to see though clothes really do exist now! Wow, I wonder if this technology will be used by perverts in the future!

 

[hjames]

Well, one main difference is in lens materials. Beyond 2-3um, glass just doesn't work and lenses need to be made out of more exotic materials. Silicon is apparently a really good *lens* material for thermal cameras.