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gregz
Guest
Guest
Mon Jan 16, 2012 3:32 am
John Larkin <jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
Quote:
On Sun, 15 Jan 2012 01:59:26 +0000 (UTC), gregz <zekor_at_comcast.net
wrote:
miso <miso_at_sushi.com> wrote:
On 1/13/2012 12:50 AM, boB wrote:
On Thu, 12 Jan 2012 20:44:22 -0800, miso<miso_at_sushi.com> wrote:
On 1/12/2012 11:53 AM, John Larkin wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
In the dark ages, at least for chips, we used liquid crystals to find
hot spots. If the device on the chip wasn't getting hot enough for a
phase change, you would bring a soldering iron nearby to "prime the pump".
I also use a hot spot finder with audible enunciator...
If the component is very hot when the finger-probe is drug over the
top of the hot part, it emits a loud "OUCH !"
boB
I was thinking for board level use, there should be some device to wave
over components. It would have to be fast, not a thermal couple. Maybe PIR film.
I have used a near field IR thermometer with a hole in some cardboard for a
lens. Holding it less than an inch away from components.
Greg
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
wrote:
miso <miso_at_sushi.com> wrote:
On 1/13/2012 12:50 AM, boB wrote:
On Thu, 12 Jan 2012 20:44:22 -0800, miso<miso_at_sushi.com> wrote:
On 1/12/2012 11:53 AM, John Larkin wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
In the dark ages, at least for chips, we used liquid crystals to find
hot spots. If the device on the chip wasn't getting hot enough for a
phase change, you would bring a soldering iron nearby to "prime the pump".
I also use a hot spot finder with audible enunciator...
If the component is very hot when the finger-probe is drug over the
top of the hot part, it emits a loud "OUCH !"
boB
I was thinking for board level use, there should be some device to wave
over components. It would have to be fast, not a thermal couple. Maybe PIR film.
I have used a near field IR thermometer with a hole in some cardboard for a
lens. Holding it less than an inch away from components.
Greg
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
Anyway, it worked for me. I forget the exact configuration, but there were
some opamps that got uncomfortably warm to the touch. I think I actually
used a tube, now that I think about it.
Greg
John Larkin
Guest
Guest
Mon Jan 16, 2012 4:19 am
On Mon, 16 Jan 2012 02:10:07 +0000 (UTC), gregz <zekor_at_comcast.net>
wrote:
Quote:
John Larkin <jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote:
On Sun, 15 Jan 2012 01:59:26 +0000 (UTC), gregz <zekor_at_comcast.net
wrote:
miso <miso_at_sushi.com> wrote:
On 1/13/2012 12:50 AM, boB wrote:
On Thu, 12 Jan 2012 20:44:22 -0800, miso<miso_at_sushi.com> wrote:
On 1/12/2012 11:53 AM, John Larkin wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
In the dark ages, at least for chips, we used liquid crystals to find
hot spots. If the device on the chip wasn't getting hot enough for a
phase change, you would bring a soldering iron nearby to "prime the pump".
I also use a hot spot finder with audible enunciator...
If the component is very hot when the finger-probe is drug over the
top of the hot part, it emits a loud "OUCH !"
boB
I was thinking for board level use, there should be some device to wave
over components. It would have to be fast, not a thermal couple. Maybe PIR film.
I have used a near field IR thermometer with a hole in some cardboard for a
lens. Holding it less than an inch away from components.
Greg
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
Anyway, it worked for me. I forget the exact configuration, but there were
some opamps that got uncomfortably warm to the touch. I think I actually
used a tube, now that I think about it.
Greg
On Sun, 15 Jan 2012 01:59:26 +0000 (UTC), gregz <zekor_at_comcast.net
wrote:
miso <miso_at_sushi.com> wrote:
On 1/13/2012 12:50 AM, boB wrote:
On Thu, 12 Jan 2012 20:44:22 -0800, miso<miso_at_sushi.com> wrote:
On 1/12/2012 11:53 AM, John Larkin wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
In the dark ages, at least for chips, we used liquid crystals to find
hot spots. If the device on the chip wasn't getting hot enough for a
phase change, you would bring a soldering iron nearby to "prime the pump".
I also use a hot spot finder with audible enunciator...
If the component is very hot when the finger-probe is drug over the
top of the hot part, it emits a loud "OUCH !"
boB
I was thinking for board level use, there should be some device to wave
over components. It would have to be fast, not a thermal couple. Maybe PIR film.
I have used a near field IR thermometer with a hole in some cardboard for a
lens. Holding it less than an inch away from components.
Greg
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
Anyway, it worked for me. I forget the exact configuration, but there were
some opamps that got uncomfortably warm to the touch. I think I actually
used a tube, now that I think about it.
Greg
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
Jan Panteltje
Guest
Guest
Mon Jan 16, 2012 10:45 am
On a sunny day (Sun, 15 Jan 2012 14:28:36 -0500) it happened Phil Hobbs
<pcdhSpamMeSenseless_at_electrooptical.net> wrote in
<4F1328E4.2CB7B88_at_electrooptical.net>:
Quote:
Jan Panteltje wrote:
On a sunny day (Sun, 15 Jan 2012 08:53:35 -0800) it happened John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
g116h7l5ivc9n7m7bdkcp7dgndffbpo2mi_at_4ax.com>:
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
No, 'camera obscura' should also work for IR.
Except that the cardboard is also incandescent in the IR, unlike the
visible. "Camera obscura" means "dark room", and there ain't no such
animal in the thermal IR, unless you use your cryocooler!
On a sunny day (Sun, 15 Jan 2012 08:53:35 -0800) it happened John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
g116h7l5ivc9n7m7bdkcp7dgndffbpo2mi_at_4ax.com>:
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
No, 'camera obscura' should also work for IR.
Except that the cardboard is also incandescent in the IR, unlike the
visible. "Camera obscura" means "dark room", and there ain't no such
animal in the thermal IR, unless you use your cryocooler!
Sure, you are right.
But is not this temperature difference way above thermal background?
I mean if you look at a component 30°C above ambient?
Seems a lot cheaper than a geranium plant lens...
Sort of like the idea.
Jan Panteltje
Guest
Guest
Mon Jan 16, 2012 10:45 am
John Larkin:
Quote:
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
There's a reason people pay $1000 for a germanium lens.
John
You are wrong, Jim is right, he just published a beautiful design.
Phil Hobbs
Guest
Guest
Mon Jan 16, 2012 4:30 pm
Jan Panteltje wrote:
Quote:
On a sunny day (Sun, 15 Jan 2012 14:28:36 -0500) it happened Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote in
4F1328E4.2CB7B88_at_electrooptical.net>:
Jan Panteltje wrote:
On a sunny day (Sun, 15 Jan 2012 08:53:35 -0800) it happened John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
g116h7l5ivc9n7m7bdkcp7dgndffbpo2mi_at_4ax.com>:
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
No, 'camera obscura' should also work for IR.
Except that the cardboard is also incandescent in the IR, unlike the
visible. "Camera obscura" means "dark room", and there ain't no such
animal in the thermal IR, unless you use your cryocooler!
Sure, you are right.
But is not this temperature difference way above thermal background?
I mean if you look at a component 30°C above ambient?
Seems a lot cheaper than a geranium plant lens...
Sort of like the idea.
If you hold the camera and cardboard still, and wave the board around in
front of it till you get the largest signal, you've found the hot spot.
Of course you can do the same with your upper lip or the back of your
hand.
The sensitivity of a pinhole camera goes down as the projected solid
angle of the source, so if your hole subtends 1 degree out of a 30
degree FOV, your sensitivity goes down by a factor of
(sin(1 deg)/sin(30 deg))**2 = 0.0012.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
John Larkin
Guest
Guest
Mon Jan 16, 2012 4:48 pm
On Mon, 16 Jan 2012 09:45:18 GMT, Jan Panteltje
<pNaonStpealmtje_at_yahoo.com> wrote:
Quote:
John Larkin:
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
You are wrong, Jim is right, he just published a beautiful design.
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
You are wrong, Jim is right, he just published a beautiful design.
And it only took him a week to do it!
John
Robert Macy
Guest
Guest
Mon Jan 16, 2012 10:27 pm
On Jan 15, 7:10 pm, gregz <ze...@comcast.net> wrote:
Quote:
Robert Macy <robert.a.m...@gmail.com> wrote:
On Jan 12, 12:53 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
Doesn't CenTec, out of China, make a thermal imager for REALLY cheap,
as I recall $299 or such.
I was searching for that !!!!!!!!
Greg
On Jan 12, 12:53 pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
Thermal imagers, from Fluke, Flir, and Wahl, have come down hugely in
price in the last couple of years, with decent looking units around
$2500 now. An imager is a fabulous tool to have around.
John
Doesn't CenTec, out of China, make a thermal imager for REALLY cheap,
as I recall $299 or such.
I was searching for that !!!!!!!!
Greg
Greg,
From memory...I was searching Harbor Freight for a Nail Locator [not a
stud finder] and the same page that showed an electronic 5 in 1
product from CenTec showed a section of 'what others bought who bought
this' or such
I 'think' one item was a thermal imager and the price was incredible.
Somewhere also listed was a miniature fibre optic camera with some 6
to 8 foot run-length.at incredible price, too.
So, check Harbor Freight.
Jan Panteltje
Guest
Guest
Tue Jan 17, 2012 10:25 am
On a sunny day (Mon, 16 Jan 2012 10:30:31 -0500) it happened Phil Hobbs
<pcdhSpamMeSenseless_at_electrooptical.net> wrote in
<4F144297.E68D93C9_at_electrooptical.net>:
Quote:
Jan Panteltje wrote:
On a sunny day (Sun, 15 Jan 2012 14:28:36 -0500) it happened Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote in
4F1328E4.2CB7B88_at_electrooptical.net>:
Jan Panteltje wrote:
On a sunny day (Sun, 15 Jan 2012 08:53:35 -0800) it happened John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
g116h7l5ivc9n7m7bdkcp7dgndffbpo2mi_at_4ax.com>:
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
No, 'camera obscura' should also work for IR.
Except that the cardboard is also incandescent in the IR, unlike the
visible. "Camera obscura" means "dark room", and there ain't no such
animal in the thermal IR, unless you use your cryocooler!
Sure, you are right.
But is not this temperature difference way above thermal background?
I mean if you look at a component 30°C above ambient?
Seems a lot cheaper than a geranium plant lens...
Sort of like the idea.
If you hold the camera and cardboard still, and wave the board around in
front of it till you get the largest signal, you've found the hot spot.
Of course you can do the same with your upper lip or the back of your
hand.
The sensitivity of a pinhole camera goes down as the projected solid
angle of the source, so if your hole subtends 1 degree out of a 30
degree FOV, your sensitivity goes down by a factor of
(sin(1 deg)/sin(30 deg))**2 = 0.0012.
On a sunny day (Sun, 15 Jan 2012 14:28:36 -0500) it happened Phil Hobbs
pcdhSpamMeSenseless_at_electrooptical.net> wrote in
4F1328E4.2CB7B88_at_electrooptical.net>:
Jan Panteltje wrote:
On a sunny day (Sun, 15 Jan 2012 08:53:35 -0800) it happened John Larkin
jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
g116h7l5ivc9n7m7bdkcp7dgndffbpo2mi_at_4ax.com>:
In as much as the cardboard restricts the field of view, you are
measuring the temperature of the cardboard.
John
No, 'camera obscura' should also work for IR.
Except that the cardboard is also incandescent in the IR, unlike the
visible. "Camera obscura" means "dark room", and there ain't no such
animal in the thermal IR, unless you use your cryocooler!
Sure, you are right.
But is not this temperature difference way above thermal background?
I mean if you look at a component 30°C above ambient?
Seems a lot cheaper than a geranium plant lens...
Sort of like the idea.
If you hold the camera and cardboard still, and wave the board around in
front of it till you get the largest signal, you've found the hot spot.
Of course you can do the same with your upper lip or the back of your
hand.
The sensitivity of a pinhole camera goes down as the projected solid
angle of the source, so if your hole subtends 1 degree out of a 30
degree FOV, your sensitivity goes down by a factor of
(sin(1 deg)/sin(30 deg))**2 = 0.0012.
Yes that does not leave much now does it....
Quote:
Cheers
Phil Hobbs
Phil Hobbs
Jan Panteltje
Guest
Guest
Tue Jan 17, 2012 10:26 am
On a sunny day (Mon, 16 Jan 2012 07:48:39 -0800) it happened John Larkin
<jjlarkin_at_highNOTlandTHIStechnologyPART.com> wrote in
<mlh8h71ij2dpcooeuq1skmf6dgm2qu2l2a_at_4ax.com>:
Quote:
On Mon, 16 Jan 2012 09:45:18 GMT, Jan Panteltje
pNaonStpealmtje_at_yahoo.com> wrote:
John Larkin:
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
You are wrong, Jim is right, he just published a beautiful design.
:-)
And it only took him a week to do it!
John
pNaonStpealmtje_at_yahoo.com> wrote:
John Larkin:
Then you'll measure mostly the temperature of the wall of the tube.
There's a reason people pay $1000 for a germanium lens.
John
You are wrong, Jim is right, he just published a beautiful design.
:-)
And it only took him a week to do it!
John
But Jim has other things top do, he is working on a chip IIRC.
elektroda.net NewsGroups Forum Index - Electronics Design - thermal imagers
