I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood

"Woody Brison" wrote in message
oups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood


Don't know about that but I used to know someone who used his tongue as a
voltmeter for determining the voltage of batteries.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"Woody Brison" wrote in message
oups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to 50
Very warm ... 50 to 60
Hot ... 70
Makes a blister... 100 and up

Does anybody have the numbers that go in here?

I added some above. For most folks, 70 is about as hot as one can stand for
a second or two (does depend on calluses, though).

On 1 Nov 2005 10:29:32 -0800, "Woody Brison"
wrote:

I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood

I can touch a smooth metal surface at 50C forever, 60C for about 2
seconds, and can interpolate pretty well berween.

Calibrate yourself!

John

On Tue, 01 Nov 2005 12:12:30 -0800, John Larkin
wrote:

On 1 Nov 2005 10:29:32 -0800, "Woody Brison"
wrote:

I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood

I can touch a smooth metal surface at 50C forever, 60C for about 2
seconds, and can interpolate pretty well berween.

Calibrate yourself!

John


Mmm...

I have measured the "surface" temp of a 60W typical bulb and came out
appox 80C with temp probe attachment for multimeter.

Cheers, Wizard

I used to do temperature testing of RF equipment in a walkin temperature
chamber and changed cables at 80 deg C. Screwing and unscrewing N
connectors bare-handed was a real challenge. 80 C is definitely in the hot
range.

I also once had to install some electronics on an all steel crane while it
was operating over a furnace. The temperature on the crane was 155 F or
about 68 C.


"Charles Schuler" wrote in message
...

"Woody Brison" wrote in message
oups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to 50
Very warm ... 50 to 60
Hot ... 70
Makes a blister... 100 and up

Does anybody have the numbers that go in here?

I added some above. For most folks, 70 is about as hot as one can stand
for a second or two (does depend on calluses, though).

Woody Brison wrote:

I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?
Very Hot .........."Sun of a Bitch Ar!"

Does anybody have the numbers that go in here?

Wood



--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

I can touch a smooth metal surface at 50C forever, 60C for about 2
seconds, and can interpolate pretty well berween.


Confirmed.

50C is now the legislated limit for hot water systems as it will not scold.
60C maybe 5 secs max. depending on your level of tolerance to pain. It is
the legislated as the cut off point as well.

On Tue, 1 Nov 2005 18:51:18 -0000, "N Cook"
wrote:


"Woody Brison" wrote in message
roups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood


Don't know about that but I used to know someone who used his tongue as a
voltmeter for determining the voltage of batteries.

One can check those small 9V batteries with pretty good accuracy.
It became habit forming just like jolts from the old 75 and 90
volt B batteries. What else can you legally do when a kid at
home?

I pothe hethe the guyth thut torkth like thus

David

N Cook wrote:




Don't know about that but I used to know someone who used his tongue as a
voltmeter for determining the voltage of batteries.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Hi!

I have measured the "surface" temp of a 60W typical bulb and came out
appox 80C with temp probe attachment for multimeter.

I can second that. My IR thermometer (at a few inches) said my 130V 60W
bulbs were between 86 and 90 degrees C.

William

Yea. 113F and you will let go. Blisters at 150F.. However, my wife is a
cook and most of her finger tips have been burnt over the years. She can
hold 150 for several seconds. I know. She passes hot dishes to me and I drop
them.

Harold


"Woody Brison" wrote in message
oups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood

On Wed, 02 Nov 2005 22:30:08 +0900, H. Dziardziel
wrote:

On Tue, 1 Nov 2005 18:51:18 -0000, "N Cook"
wrote:


"Woody Brison" wrote in message
groups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to ?
Very warm ... ?
Hot ... ?
Makes a blister... ?

Does anybody have the numbers that go in here?

Wood


Don't know about that but I used to know someone who used his tongue as a
voltmeter for determining the voltage of batteries.

One can check those small 9V batteries with pretty good accuracy.
It became habit forming just like jolts from the old 75 and 90
volt B batteries. What else can you legally do when a kid at
home?

Here we go again...it wasn't a pleasant experience when I checked my
old cellphone PS...10.6 V, 850 mA...I thought that the top of my head
was going to come off. :-)

Tom

On Tue, 1 Nov 2005 15:08:35 -0500, "Charles Schuler"
wrote:


"Woody Brison" wrote in message
roups.com...
I vaguely remember an engineer mentioning an old rule of thumb
for quickly estimating temperatures on circuit boards: you put
your finger on a component, and it went something like this:

Feels cool ... 25 to 35 deg C
Neutral ... 37
Warm ... 40 to 50
Very warm ... 50 to 60

I have skin on my fingertips that's like a baby's skin...those
well-known Samsung vertical IC heatsinks are hotter than I can handle.

Tom

Hot ... 70
Makes a blister... 100 and up

Does anybody have the numbers that go in here?

I added some above. For most folks, 70 is about as hot as one can stand for
a second or two (does depend on calluses, though).