I read somewhere that when a IC develops a short it will start to heat up.
So I was thinking that maybe one of the new laser type of Temp probes might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the distance
and spot being measured is what to look for. Any particular model or ideas
a long this line?

Thanks

"Russ" writes:

I read somewhere that when a IC develops a short it will start to heat up.
So I was thinking that maybe one of the new laser type of Temp probes might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the distance
and spot being measured is what to look for. Any particular model or ideas
a long this line?

This doesn't seem to be particulalry useful unless you have a reverence
thermal map of a working unit. Some parts run hotter than others under
normal conditions. And, what is going on in the electronics will also
affect the heat generated.

Any significant overheating will be obvious to a reasonably well calibrated
finger.

--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.

Sam Goldwasser wrote:
"Russ" writes:


I read somewhere that when a IC develops a short it will start to heat up.
So I was thinking that maybe one of the new laser type of Temp probes might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the distance
and spot being measured is what to look for. Any particular model or ideas
a long this line?


This doesn't seem to be particulalry useful unless you have a reverence
thermal map of a working unit. Some parts run hotter than others under
normal conditions. And, what is going on in the electronics will also
affect the heat generated.

Any significant overheating will be obvious to a reasonably well calibrated
finger.

Might wanna be careful about sticking that well calibrated finger into
an off-line switching power supply...or Horizontal Output Transistor.
I'll use my IR probe, thank you.

You might find other uses for an IR probe. I use mine to find heat
leaks in the house, in cooking, auto repair etc. Handy little gadgets.
mike


--- sam | Sci.Electronics.Repair FAQ Mirror: http://repairfaq.ece.drexel.edu/
Repair | Main Table of Contents: http://repairfaq.ece.drexel.edu/REPAIR/
+Lasers | Sam's Laser FAQ: http://repairfaq.ece.drexel.edu/sam/lasersam.htm
| Mirror Sites: http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.



--
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with links. Delete this sig when replying.
..
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Mike,

Do you think any model will work or should I buy one of the expensive ones?
They have them from around $40.00 and up. It would be cool when working on
a pinball if I could point my thermal laser probe at all of the transistors
and find the one that isn't working.

Thanks
Russ
"mike" wrote in message
...
Sam Goldwasser wrote:
"Russ" writes:


I read somewhere that when a IC develops a short it will start to heat
up. So I was thinking that maybe one of the new laser type of Temp probes
might help in troubleshooting. Are they sensitive enough? Can they
isolate a small 1 inch square area without picking up things close by? I
talked to one company and they said a large 12:1 or higher ration between
the distance and spot being measured is what to look for. Any particular
model or ideas a long this line?


This doesn't seem to be particulalry useful unless you have a reverence
thermal map of a working unit. Some parts run hotter than others under
normal conditions. And, what is going on in the electronics will also
affect the heat generated.

Any significant overheating will be obvious to a reasonably well
calibrated
finger.

Might wanna be careful about sticking that well calibrated finger into an
off-line switching power supply...or Horizontal Output Transistor. I'll
use my IR probe, thank you.

You might find other uses for an IR probe. I use mine to find heat leaks
in the house, in cooking, auto repair etc. Handy little gadgets.
mike


--- sam | Sci.Electronics.Repair FAQ Mirror:
http://repairfaq.ece.drexel.edu/ Repair | Main Table of Contents:
http://repairfaq.ece.drexel.edu/REPAIR/ +Lasers | Sam's Laser FAQ:
http://repairfaq.ece.drexel.edu/sam/lasersam.htm | Mirror Sites:
http://repairfaq.ece.drexel.edu/REPAIR/F_mirror.html

Note: These links are hopefully temporary until we can sort out the
excessive
traffic on Repairfaq.org.

Important: Anything sent to the email address in the message header above
is
ignored unless my full name is included in the subject line. Or, you can
contact me via the Feedback Form in the FAQs.



--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
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Wanted, PCMCIA SCSI Card for HP m820 CDRW.
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On Sun, 27 Feb 2005 07:14:57 GMT, "Russ"
wrote:

I read somewhere that when a IC develops a short it will start to heat up.
So I was thinking that maybe one of the new laser type of Temp probes might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the distance
and spot being measured is what to look for. Any particular model or ideas
a long this line?

Thanks


I use the finger test and have for thirty years,if you want to be more
precise you can buy small square temp strips that you stick on top of
the IC.Readout is the same as a medical digi.thermometer.Got some five
years ago as they are cheap,but never used them.Use your finger tip
away from the hot chassis.To hot to touch,it's bad!

If the IC gets too hot it may be a problem or fault with the associated
circuitry..... the IC is not the only suspect here when it gets too hot.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


"Seafarer" wrote in message
...
On Sun, 27 Feb 2005 07:14:57 GMT, "Russ"
wrote:

I read somewhere that when a IC develops a short it will start to heat
up.
So I was thinking that maybe one of the new laser type of Temp probes
might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the
distance
and spot being measured is what to look for. Any particular model or
ideas
a long this line?

Thanks


I use the finger test and have for thirty years,if you want to be more
precise you can buy small square temp strips that you stick on top of
the IC.Readout is the same as a medical digi.thermometer.Got some five
years ago as they are cheap,but never used them.Use your finger tip
away from the hot chassis.To hot to touch,it's bad!

Russ wrote:
Mike,

Do you think any model will work or should I buy one of the expensive ones?
They have them from around $40.00 and up. It would be cool when working on
a pinball if I could point my thermal laser probe at all of the transistors
and find the one that isn't working.

Thanks
Russ

There are a bunch of issues.
The spot/distance ratio is critical. At the distance of measurement,
the spot size has to be small enough to measure just the thing you want.
But as it gets smaller, you have trouble aiming it. Even with a laser,
there's an offset that causes parallex error. The sense spot can't be
in the same place as the laser spot at all distances.

Emissivity relates to how well a particular material and surface
treatment radiates relative to a black body. Most cheapo units are
fixed at .95. More expensive ones have a calibration adjustment, but
that won't help if you don't know what to set it at.
Point it at a shiny aluminum heat sink and your reading won't be
anywhere near accurate. It's a relative measurement for similar
materials only.

In most cases, you have no idea what 'normal' temperature is.
You can't tell if the problem is the device, a loose mounting bolt,
something else causing the overheat.

"back in the day" story alert....

Once tried to measure the temperature of a circuit board with an early
IR video scanner. Result was dismal because of the widly varying
emissivities.
Sprayed the whole board with spray-on foot powder.
Worked great cause it normalized emissivity.
Problem was that I couldn't wash the stuff of when I was done.
Ended up scrapping the board...very expensive temperature test.

Bottom line,
I use mine more to check the temperature of my coffee when I nuke it
prior to pouring it into the thermos. Fun toy, but relatively little
used in electronic diagnostics.
mike


--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
.
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
htremovethistp://www.geocities.com/SiliconValley/Monitor/4710/







--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
htremovethistp://www.geocities.com/SiliconValley/Monitor/4710/

Mike,

Thanks for the feedback. Another idea of mine that doesn't seem to be
working out. I did order the Fluke temp probe, but not the IR one. I
almost ordered the IR one but after reading your post I am glad I didn't. I
guess I will just use the probe for coffee and tea also.

Thanks
Russ
"mike" wrote in message
...
Russ wrote:
Mike,

Do you think any model will work or should I buy one of the expensive
ones? They have them from around $40.00 and up. It would be cool when
working on a pinball if I could point my thermal laser probe at all of
the transistors and find the one that isn't working.

Thanks
Russ

There are a bunch of issues.
The spot/distance ratio is critical. At the distance of measurement,
the spot size has to be small enough to measure just the thing you want.
But as it gets smaller, you have trouble aiming it. Even with a laser,
there's an offset that causes parallex error. The sense spot can't be
in the same place as the laser spot at all distances.

Emissivity relates to how well a particular material and surface treatment
radiates relative to a black body. Most cheapo units are
fixed at .95. More expensive ones have a calibration adjustment, but that
won't help if you don't know what to set it at.
Point it at a shiny aluminum heat sink and your reading won't be anywhere
near accurate. It's a relative measurement for similar materials only.

In most cases, you have no idea what 'normal' temperature is.
You can't tell if the problem is the device, a loose mounting bolt,
something else causing the overheat.

"back in the day" story alert....

Once tried to measure the temperature of a circuit board with an early IR
video scanner. Result was dismal because of the widly varying
emissivities.
Sprayed the whole board with spray-on foot powder.
Worked great cause it normalized emissivity.
Problem was that I couldn't wash the stuff of when I was done.
Ended up scrapping the board...very expensive temperature test.

Bottom line,
I use mine more to check the temperature of my coffee when I nuke it prior
to pouring it into the thermos. Fun toy, but relatively little used in
electronic diagnostics.
mike


--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
.
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
htremovethistp://www.geocities.com/SiliconValley/Monitor/4710/







--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
.
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted, 12.1" LCD for Gateway Solo 5300. Samsung LT121SU-121
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
htremovethistp://www.geocities.com/SiliconValley/Monitor/4710/

A few times the finger thing worked real well for me. One was a pinball
transistor It was so hot it burned my finger. I guess I was wondering if
something more sensitive would be helpfull.
Thanks for input
Russ
"Seafarer" wrote in message
...
On Sun, 27 Feb 2005 07:14:57 GMT, "Russ"
wrote:

I read somewhere that when a IC develops a short it will start to heat up.
So I was thinking that maybe one of the new laser type of Temp probes
might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked to
one company and they said a large 12:1 or higher ration between the
distance
and spot being measured is what to look for. Any particular model or
ideas
a long this line?

Thanks


I use the finger test and have for thirty years,if you want to be more
precise you can buy small square temp strips that you stick on top of
the IC.Readout is the same as a medical digi.thermometer.Got some five
years ago as they are cheap,but never used them.Use your finger tip
away from the hot chassis.To hot to touch,it's bad!

Good point. Thank you.
"sofie" wrote in message
...
If the IC gets too hot it may be a problem or fault with the associated
circuitry..... the IC is not the only suspect here when it gets too hot.
--
Best Regards,
Daniel Sofie
Electronics Supply & Repair
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -


"Seafarer" wrote in message
...
On Sun, 27 Feb 2005 07:14:57 GMT, "Russ"
wrote:

I read somewhere that when a IC develops a short it will start to heat
up.
So I was thinking that maybe one of the new laser type of Temp probes
might
help in troubleshooting. Are they sensitive enough? Can they isolate a
small 1 inch square area without picking up things close by? I talked
to
one company and they said a large 12:1 or higher ration between the
distance
and spot being measured is what to look for. Any particular model or
ideas
a long this line?

Thanks


I use the finger test and have for thirty years,if you want to be more
precise you can buy small square temp strips that you stick on top of
the IC.Readout is the same as a medical digi.thermometer.Got some five
years ago as they are cheap,but never used them.Use your finger tip
away from the hot chassis.To hot to touch,it's bad!

If you get one, get a good one. Most IR guns with 12/1 ratio will not
work. It depends on the focal point size. Generally 12/1 guns have a
focal point of about 3" meaning you are measuring the average
temperature over a 3" area, plus many the laser beam is offset somewhat
from the actual point you are measuring. Raytek makes some nice guns.
Two that work real nice are the ST80 with 50/1, and the ST25 Autopro. I
use the ST80 sometimes when I suspect something heating on a board but
can't quite pinpoint it. Works nice and easy.
Russ wrote:
A few times the finger thing worked real well for me. One was a
pinball
transistor It was so hot it burned my finger. I guess I was
wondering if
something more sensitive would be helpfull.
Thanks for input
Russ
"Seafarer" wrote in message
...
On Sun, 27 Feb 2005 07:14:57 GMT, "Russ"
wrote:

I read somewhere that when a IC develops a short it will start to
heat up.
So I was thinking that maybe one of the new laser type of Temp
probes
might
help in troubleshooting. Are they sensitive enough? Can they
isolate a
small 1 inch square area without picking up things close by? I
talked to
one company and they said a large 12:1 or higher ration between the

distance
and spot being measured is what to look for. Any particular model
or
ideas
a long this line?

Thanks


I use the finger test and have for thirty years,if you want to be
more
precise you can buy small square temp strips that you stick on top
of
the IC.Readout is the same as a medical digi.thermometer.Got some
five
years ago as they are cheap,but never used them.Use your finger tip
away from the hot chassis.To hot to touch,it's bad!

"Russ" bravely wrote to "All" (22 Apr 05 06:56:36)
--- on the heady topic of " Temp probe for troubleshooting"

Ru From: "Russ"
Ru Xref: aeinews sci.electronics.repair:46218

Ru A few times the finger thing worked real well for me. One was a
Ru pinball transistor It was so hot it burned my finger. I guess I was
Ru wondering if something more sensitive would be helpfull.

A wax crayon... Wax melts just under the boiling point of water around
180-200'F. IIRC there are even special wax mixtures calibrated for
specific temperatures. These are used to calibrate furnaces, ovens,
etc.

Many ceramic capacitors are highly sensitive to radiant heat and their
capacitance value will drift according to temperature. When used in a
bridge or a counter even the heat from a hand can be readily detected.

IR diodes are also sensitive to radiant heat but have to be compared
to a known temperature.

A*s*i*m*o*v

.... 'Keep the smoke inside.' -- 1st Rule of Electronics.