Economy thermal imager?

[Fester Bestertester]

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

 

[Lostgallifreyan]

Fester Bestertester <fbt@fbt.net> wrote in
news:0001HW.C68CBEC10010FF2AB08A39AF@news.eternal-september.org:

There are instructions on the 'net I've seen for removing the IR filter
from a digicam's digitizer chip so as to allow recording of the IR
spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to
be anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for
industrial purposes, such as looking for hot spots in equipment? Some
application where the temperature difference is large.

Thanks.

Probably not. While it's common practise to remove an IR filter to image what
a near-IR laser or other diode is doing, it wouldn't work for long-wave IR
like a CO2 laser and the emissions from something hot, unless it was almost
hot enough to be visible anyway. But try it, you might get enough milage out
of it. it will be cheaper to try it that to find out what you need if it
doesn't work so you have to try it, no?

 

[Martin Brown]

Fester Bestertester wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

A *much* broader spectrum out to long wave IR and also a silicon lens.
Glass does not transmit the wavelengths needed for thermal imaging.
There is a good reason why they are so expensive.

You can do near IR with a modified digicam and a low pass filter -
enough to make diagnosis of foliage diseases in trees perhaps but
nothing like enough to see temperature differences unless the target was
almost at red heat. I doubt if a soldering iron would show up at all on
a normal digicam CCD in the IR.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

You can buy relatively cheap non contact IR thermometers and use a servo
to scan one to build up a low resolution thermal image.

Regards,
Martin Brown

 

[Jupiter Jaq]

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester <fbt@fbt.net>
wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

More likely, you need to PLACE an IR filter in front of a camera image
chip, and boost its gain.

If you know where your hot spots develop, you can mount properly pointed,
dedicated IR sensors without the need for imagery.

 

[Nicholas Kinar]

You can buy relatively cheap non contact IR thermometers and use a servo
to scan one to build up a low resolution thermal image.

Melexis makes non-expensive IR thermometers:

http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Digital_plug__play_infrared_thermometer_in_a_TO-can_615.aspx
http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Digital_plug__play_infrared_thermometer_in_an_ultra_small_TO-can_685.aspx
http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Infrared_Sensor_IC_19.aspx

 

[Archimedes' Lever]

On Wed, 22 Jul 2009 16:15:56 -0600, Nicholas Kinar <n.kinar@usask.ca>
wrote:

You can buy relatively cheap non contact IR thermometers and use a servo
to scan one to build up a low resolution thermal image.

Melexis makes non-expensive IR thermometers:

http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Digital_plug__play_infrared_thermometer_in_a_TO-can_615.aspx
http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Digital_plug__play_infrared_thermometer_in_an_ultra_small_TO-can_685.aspx
http://www.melexis.com/Sensor_ICs_Infrared_and_Optical/Infrared_Thermometers/Infrared_Sensor_IC_19.aspx

Those are the transducers themselves. Not much good on their own. All
appear to sport a Germanium window, though the first one has a small
cartoon superimposed over it.

Harbor freight sells nice IR thermometer units. You can get the
fresnel jobs and point at the target from the right distance, and remove
the need to "scan" a rudimentary image. like some have described. It
would sense the change anywhere in its field of view.

 

[Archimedes' Lever]

On Wed, 22 Jul 2009 15:36:44 -0700 (PDT), "miso@sushi.com"
<miso@sushi.com> wrote:

On Jul 22, 1:04 pm, Fester Bestertester <f...@fbt.net> wrote:
There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

The Sony Exview B&W CCD have response beyond a micron. Since a
digital camera or camcorder will have a RGB matrix, only a fraction of
the pixels will have IR response, so the low resolution of NTSC camera
isn't all that crappy since at least all the pixels will have some
response.

You can see a soldering iron in the dark with one of these exview
CCDs, but this is only because the iron is stinkin hot and the black
body radiation has a long exponential tail. That is, you don't see the
peak of the thermal image. Averaging the image helps since you are
dealing with a noisy signal.
http://www.supercircuits.com/Security-Cameras/Specialty-Security-
Cameras/PC164C

Don't set your expectations too high as far as thermal sensing goes.
Otherwise, these low light cameras are pretty cool, certainly on par
with gen 1 NV.

Might as well buy the real IR imagers that the security camera folks

are pushing now, if you are going to do that.

I think they sell them by the box at Frys'.

 

[Archimedes' Lever]

On Wed, 22 Jul 2009 15:36:44 -0700 (PDT), "miso@sushi.com"
<miso@sushi.com> wrote:

Don't set your expectations too high as far as thermal sensing goes.

http://www.frys.com/product/5820453?site=sr:SEARCH:MAIN_RSLT_PG

 

[miso@sushi.com]

On Jul 22, 1:04 pm, Fester Bestertester <f...@fbt.net> wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

The Sony Exview B&W CCD have response beyond a micron. Since a
digital camera or camcorder will have a RGB matrix, only a fraction of
the pixels will have IR response, so the low resolution of NTSC camera
isn't all that crappy since at least all the pixels will have some
response.

You can see a soldering iron in the dark with one of these exview
CCDs, but this is only because the iron is stinkin hot and the black
body radiation has a long exponential tail. That is, you don't see the
peak of the thermal image. Averaging the image helps since you are
dealing with a noisy signal.
<http://www.supercircuits.com/Security-Cameras/Specialty-Security-
Cameras/PC164C>

Don't set your expectations too high as far as thermal sensing goes.
Otherwise, these low light cameras are pretty cool, certainly on par
with gen 1 NV.

 

[miso@sushi.com]

On Jul 22, 4:24 pm, Archimedes' Lever <OneBigLe...@InfiniteSeries.Org>
wrote:

On Wed, 22 Jul 2009 15:36:44 -0700 (PDT), "m...@sushi.com"

m...@sushi.com> wrote:

Don't set your expectations too high as far as thermal sensing goes.

http://www.frys.com/product/5820453?site=sr:SEARCH:MAIN_RSLT_PG

That isn't the same thing. This all gets really confusing unless you
sit back and look at what all these objects (NV, IR, thermal) do. NV
is light amplification. It has a bit of IR sensitivity, so low grade
NV uses IR illuminators. Thermal imaging is in the 10um range, It
really detects infrared. Cameras like what Fry;s is selling are just
CCDs with IR illuminators. Real NV just amplifies star light.

The deal is IR illuminators don't go very far, so if you depend on IR
illumination, you can't see very far and you are a serious target for
anyone else with a CCD, NV, or thermal. Your life expectancy in war
time would be that of a Marine flame thrower.

The original poster is trying to detect IR, so painting with IR won't
do the trick. There is also the Phil Hobbs $10 detector he posts when
this subject comes up. It's a good paper, though I don't know about
the price.

The Sony exview CCD is a very sensitive detector with just a bit of
near IR response, maybe out to a 1um, but not flat.

 

[Tim Wescott]

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester wrote:

There are instructions on the 'net I've seen for removing the IR filter
from a digicam's digitizer chip so as to allow recording of the IR
spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to
be anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for
industrial purposes, such as looking for hot spots in equipment? Some
application where the temperature difference is large.

Thanks.

No, for a variety of reasons.

Visible light spans about an octave -- something a bit shorter than 800
nanometers to something a bit shorter than 400, IIRC.

IR midwave is 3-5 microns; that's four times longer than visible light.
Glass won't transmit it so you need special lens materials, silicon
diodes won't detect it so you need special detector materials, and your
whole damn camera body glows so you have to design and build the optical
path with great care.

IR long wave (where the inexpensive bolometer-style detectors work) is
8-12 microns, and that just makes the job harder.

--
http://www.wescottdesign.com

 

Go to ebay, google probeye every once in a while. replace some small
rubber belts inside.

Find a dive shop, they can refill the hughes argon tanks for the
joule thompson cooleras they pressure test the dive tanks with HP
Argon/

About as cheap as thermal imaging gets, as low as 250$ every once in a
while.

room temperature thermal really does not kick in until you get to 3.5
microns and better home ones would cover 8-12 microns.

raytheon imagers show up, but I could never find one of the 240x320
cadillac deville ones, seems most of them died before the car made it
to the junk yards. I'm told once in a while a car dealer finds one on
the shelf and lets them go at 2400$ each


only way to make anything decent with the most of the IR motion
sensors out there is to put a chopper wheel in front of them and use
them for very close targets, they are not all that sensitive and will
see things just out of their field of view better then they would see
a far away cold room temp target. They are piezo, and thus only
respond to a AC (chopped) signal, unless you can find a newer single
element or 4x4 array bolometer ie melexys.

Phil Hobbs design rocks $ for $ compared to anything else other then
a bolometer chip.

Or if you can find a anesthesia gas analyser of the more modern
compact kind, you can find a single element sensor with a TE cooler in
the package and use a pair of galvo mirrors for scanning and and a
old lens from a laser cutting shop co2 laser for the objective lens.
The Anesthesia Analyser are usually 3-8 microns or so, but need the
cooling and a bias current and a chopper wheel, they usually have
dichroic filters on a chopper wheel for optical adsorption bands for
each gas. I've picked up the modules at my local surplus place for 50
cents from time to time, and mine are not for sale.

Steve Roberts

 

[Jupiter Jaq]

On Wed, 22 Jul 2009 18:54:04 -0700 (PDT), osr@uakron.edu wrote:

raytheon imagers show up, but I could never find one of the 240x320
cadillac deville ones,

320x240 ain't shit (the wide aspect is always first).

Mikron and FLIR were the Cadillacs.

 

On Jul 23, 1:20 am, Jupiter Jaq <Jupiter...@BuyOneGetOneFree.org>
wrote:

On Wed, 22 Jul 2009 18:54:04 -0700 (PDT), o...@uakron.edu wrote:
raytheon imagers show up, but I could never find one of the 240x320
cadillac deville ones,

320x240 ain't shit (the wide aspect is always first).

Mikron and FLIR were the Cadillacs.

And raytheon's cheapest bolometer was the one in the deville front
grill, there is a complete system from the car on ebay starting at
200$ right now, probably will be 400$ or more when the auction is
done.

I agree 320 is a waste of time, but he's asking for a hobby system.

Steve

 

[John Larkin]

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester <fbt@fbt.net>
wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

There's a reason a FLIR costs $10K.

John

 

[Jupiter Jaq]

On Thu, 23 Jul 2009 13:27:25 -0700 (PDT), osr@uakron.edu wrote:

On Jul 23, 1:20 am, Jupiter Jaq <Jupiter...@BuyOneGetOneFree.org
wrote:
On Wed, 22 Jul 2009 18:54:04 -0700 (PDT), o...@uakron.edu wrote:
raytheon imagers show up, but I could never find one of the 240x320
cadillac deville ones,

320x240 ain't shit (the wide aspect is always first).

Mikron and FLIR were the Cadillacs.

And raytheon's cheapest bolometer was the one in the deville front
grill,

Oh WOW! I thought you were actually calling a Raytheon imager product
"The Cadillac" of the crop kind of thing. I totally missed that you were
referring to it actually being a product installed onto a Caddy.

there is a complete system from the car on ebay starting at
200$ right now, probably will be 400$ or more when the auction is
done.

I agree 320 is a waste of time, but he's asking for a hobby system.

There are many out there, but shopping for the right price to get a good
value is difficult with the online world.

Hell, even at Fry's you cannot examine a working item more than half
the time. I hate that sight unseen crap!

 

[Archimedes' Lever]

On Thu, 23 Jul 2009 15:28:42 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester <fbt@fbt.net
wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

There's a reason a FLIR costs $10K.

John

Yeah... it is called greed, and the knowledge that most of your buyers
are rich government funded factions.

 

[John Larkin]

On Thu, 23 Jul 2009 18:39:02 -0700, Archimedes' Lever
<OneBigLever@InfiniteSeries.Org> wrote:

On Thu, 23 Jul 2009 15:28:42 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester <fbt@fbt.net
wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Thanks.

There's a reason a FLIR costs $10K.

John

Yeah... it is called greed, and the knowledge that most of your buyers
are rich government funded factions.

The detector is pretty exotic, and the retail price of the germanium
lens is a couple of $K.

FLIR recently bought Extech, and has a new, lower-price thermal
imager.

John

 

[Jeff Liebermann]

On Thu, 23 Jul 2009 20:47:27 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

The detector is pretty exotic, and the retail price of the germanium
lens is a couple of $K.

FLIR recently bought Extech, and has a new, lower-price thermal
imager.

<http://www.extech.com/instrument/products/alpha/IRC40.html>
$2,700 to $3,000 from many sources. Still kinda pricy but getting
there. Thanks.

 

[Jeff Liebermann]

On Wed, 22 Jul 2009 13:04:01 -0700, Fester Bestertester <fbt@fbt.net>
wrote:

There are instructions on the 'net I've seen for removing the IR filter from
a digicam's digitizer chip so as to allow recording of the IR spectrum.

Commercial thermal imagers are thousands of dollars. They don't seem to be
anything more than a digicam with a broader spectrum (IR) sensor.

Can such a modified camera be used as a cheap thermal imager for industrial
purposes, such as looking for hot spots in equipment? Some application where
the temperature difference is large.

Nope.

One of my rants covering the topic:
<http://groups.google.com/group/sci.electronics.equipment/browse_thread/thread/92c3879a53a8f9f1>

Light reading that explains how it's done. See description:
<http://www.pyrometer.com/thermatrace.html>

How the detectors and imagers work:
<http://www.omega.com/literature/transactions/volume1/thermometers1.html>

More:
<http://en.wikipedia.org/wiki/Thermography>
<http://en.wikipedia.org/wiki/Flir>

If you want cheap, I've butchered a supermarket bar code scanner into
an infrared flying spot scanner that sorta works. The problem is that
the detector is VERY slow to respond. It scans tolerably well if the
target isn't moving, but any movement results in a messy blur on the
screen.

Optics are another problem. A germanium lens is best, but I was
fairly successful with an ordinary glass lens with an IR bandpass
filter in front of it.
<http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=390073136866>

Next step is to cool the assembly as I get as much thermal glow from
the case as IR transmission through the filter.