Hi, I am becoming obsessed :-) with temperature and heat loss etc. around my
house and thought I would get an infrared thermometer to measure wall
temperatures and other things such as the temerature of overhead clouds if
possible. Any suggestions as to what type of infrared thermometer I should
get? Not too expensive as my grandson is buying it for my birthday.
Thanks Ron

On 2006-10-15 11:48:31 +0100, "Ron" said:

Hi, I am becoming obsessed :-) with temperature and heat loss etc.
around my house and thought I would get an infrared thermometer to
measure wall temperatures and other things such as the temerature of
overhead clouds if possible. Any suggestions as to what type of
infrared thermometer I should get? Not too expensive as my grandson is
buying it for my birthday.
Thanks Ron


Maplin usually have some that are fairly inexpensive.

"Ron" wrote in message
.uk...
Hi, I am becoming obsessed :-) with temperature and heat loss etc. around
my house and thought I would get an infrared thermometer to measure wall
temperatures and other things such as the temerature of overhead clouds if
possible. Any suggestions as to what type of infrared thermometer I should
get? Not too expensive as my grandson is buying it for my birthday.
Thanks Ron


maplin 30 quid

In message ,
mrcheerful
.. wrote

"Ron" wrote in message
o.uk...
Hi, I am becoming obsessed :-) with temperature and heat loss etc. around
my house and thought I would get an infrared thermometer to measure wall
temperatures and other things such as the temerature of overhead clouds if
possible.

If pointing at a clear sky you are looking through the atmosphere into
space. Space will be around absolute zero (-273 degrees C) - attenuated
by the atmosphere and limited to the range of the device. You may not
see the temperatures you expect to see

If looking at low clouds the water vapour could be acting like a mirror
and reflecting the ground temperature.


Any suggestions as to what type of infrared thermometer I should
get? Not too expensive as my grandson is buying it for my birthday.
Thanks Ron


maplin 30 quid


£40 from CPC for a smaller pocket version with a laser pointer

http://cpc.farnell.com/jsp/endecaSearch/partDetail.jsp?SKU=IN02293

Cheaper instruments @ £12 (with a smaller temperature range) can be
obtained on Ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.d...09673&ssPageNa
me=MERCOSI_VI_ROSI_PR4_PCN_BIX_Stores&refitem=2200 32649605&itemcount=4&re
fwidgetloc=closed_view_item&refwidgettype=osi_widg et
Note that the Ebay item required a 12V battery - not supplied.

My CPC device takes 2 off AAA size 1.5V batteries

Be aware that these instruments are measuring an area of diameter 3 or
4 inches when held at a distance of 2 feet away from the source.

--
Alan
news2006 {at} amac {dot} f2s {dot} com

In article ,
Alan writes:
If pointing at a clear sky you are looking through the atmosphere into
space. Space will be around absolute zero (-273 degrees C) - attenuated
by the atmosphere and limited to the range of the device. You may not
see the temperatures you expect to see

Actually, it's about 3K (-270C) due to heat left from the big bang
in the form of the cosmic microwave background. However, you won't
get a digital thermometer to register that.

If looking at low clouds the water vapour could be acting like a mirror
and reflecting the ground temperature.

No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.

If the OP isn't in a hurry for one, these things do turn up on
special offer from time to time.

--
Andrew Gabriel

Fluke do a nice one...Model 62...but it ain't cheap! Cost around £60

"Andrew Gabriel" wrote in message
...
In article ,
Alan writes:
If pointing at a clear sky you are looking through the atmosphere into
space. Space will be around absolute zero (-273 degrees C) - attenuated
by the atmosphere and limited to the range of the device. You may not
see the temperatures you expect to see

Actually, it's about 3K (-270C) due to heat left from the big bang
in the form of the cosmic microwave background. However, you won't
get a digital thermometer to register that.

If looking at low clouds the water vapour could be acting like a mirror
and reflecting the ground temperature.

No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.

If the OP isn't in a hurry for one, these things do turn up on
special offer from time to time.

--
Andrew Gabriel

Andy Hall wrote:

On 2006-10-15 11:48:31 +0100, "Ron" said:

Hi, I am becoming obsessed :-) with temperature and heat loss etc.
around my house and thought I would get an infrared thermometer to
measure wall temperatures and other things such as the temerature of
overhead clouds if possible. Any suggestions as to what type of
infrared thermometer I should get? Not too expensive as my grandson is
buying it for my birthday.
Thanks Ron



Maplin usually have some that are fairly inexpensive.

I bought one of those about 12 months ago and it is perfect for winding
up the landlord of my local real ale pub. The one thing he hates is to
be told that is serving his beer at the wrong temperature. A quick pull
of the trigger and he is convinced.

On the other hand, I did find it very difficult to balance my heating
with it. I ended up measuring the temp of the rad at point of entry and
exit. Trying to measure the pipes proved very variable.

Dave

In article ,
Dave writes:
On the other hand, I did find it very difficult to balance my heating
with it. I ended up measuring the temp of the rad at point of entry and
exit. Trying to measure the pipes proved very variable.

They don't work on bare copper (looks like a mirror to IR).

--
Andrew Gabriel

In message , Andrew Gabriel
wrote
In article ,
Dave writes:
On the other hand, I did find it very difficult to balance my heating
with it. I ended up measuring the temp of the rad at point of entry and
exit. Trying to measure the pipes proved very variable.

They don't work on bare copper (looks like a mirror to IR).



See
http://www.omega.com/prodinfo/infraredthermometer.html

Check the section on emissivity. Note also the warning about the field
of view of the sensor - for a 15 mm pipe to fill the field of view you
may have to be as close as 4 inches.
--
Alan
news2006 {at} amac {dot} f2s {dot} com

On Mon, 16 Oct 2006 23:04:12 +0100, Dave wrote:

|Andy Hall wrote:
|
| On 2006-10-15 11:48:31 +0100, "Ron" said:
|
| Hi, I am becoming obsessed :-) with temperature and heat loss etc.
| around my house and thought I would get an infrared thermometer to
| measure wall temperatures and other things such as the temerature of
| overhead clouds if possible. Any suggestions as to what type of
| infrared thermometer I should get? Not too expensive as my grandson is
| buying it for my birthday.
| Thanks Ron
|
|
|
| Maplin usually have some that are fairly inexpensive.
|
|I bought one of those about 12 months ago and it is perfect for winding
|up the landlord of my local real ale pub. The one thing he hates is to
|be told that is serving his beer at the wrong temperature. A quick pull
|of the trigger and he is convinced.

Surely it measured the temperature of the outside of the glass not the
temperature of the beer ;-)
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

Andrew Gabriel wrote:
No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.


Clouds at -40 to -50? - I don't think so. You have to go to around
30,000 feet or above to get down to those temperatures.

CRB

crb wrote:

Andrew Gabriel wrote:
No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.


Clouds at -40 to -50? - I don't think so. You have to go to around
30,000 feet or above to get down to those temperatures.

The error with low cloud is probably because their emissivity is less
than the fixed value of about 0.85-0.9 which is programmed into simple
IR thermometers. The instrument detects a certain quantity of IR
radiation, but reports it as coming from a cooler object than is
actually the case.

IR thermometers with an adjustable setting for the assumed emissivity
are much more expensive.


--
Ian White

Dave Fawthrop wrote:

On Mon, 16 Oct 2006 23:04:12 +0100, Dave wrote:

|Andy Hall wrote:
|
| On 2006-10-15 11:48:31 +0100, "Ron" said:
|
| Hi, I am becoming obsessed :-) with temperature and heat loss etc.
| around my house and thought I would get an infrared thermometer to
| measure wall temperatures and other things such as the temerature of
| overhead clouds if possible. Any suggestions as to what type of
| infrared thermometer I should get? Not too expensive as my grandson is
| buying it for my birthday.
| Thanks Ron
|
|
|
| Maplin usually have some that are fairly inexpensive.
|
|I bought one of those about 12 months ago and it is perfect for winding
|up the landlord of my local real ale pub. The one thing he hates is to
|be told that is serving his beer at the wrong temperature. A quick pull
|of the trigger and he is convinced.

Surely it measured the temperature of the outside of the glass not the
temperature of the beer ;-)

LOL Yes. But since the glass is only a container that is quite thin, the
contents will be equal to the outside of the glass.

Just wait a minute, I have a hook in my mouth and I must get rid of it :-)

Dave

On Tue, 17 Oct 2006 23:15:46 +0100, Dave
wrote:

Dave Fawthrop wrote:

Surely it measured the temperature of the outside of the glass not the
temperature of the beer ;-)

LOL Yes. But since the glass is only a container that is quite thin, the
contents will be equal to the outside of the glass.

That depends where you point the thermometer. You could point it at
the top of the beer rather than the glass, surely.

hic!

--
Frank Erskine

On Tue, 17 Oct 2006 23:15:46 +0100, Dave wrote:

|Dave Fawthrop wrote:
|
| On Mon, 16 Oct 2006 23:04:12 +0100, Dave wrote:
|
| |Andy Hall wrote:
| |
| | On 2006-10-15 11:48:31 +0100, "Ron" said:
| |
| | Hi, I am becoming obsessed :-) with temperature and heat loss etc.
| | around my house and thought I would get an infrared thermometer to
| | measure wall temperatures and other things such as the temerature of
| | overhead clouds if possible. Any suggestions as to what type of
| | infrared thermometer I should get? Not too expensive as my grandson is
| | buying it for my birthday.
| | Thanks Ron
| |
| |
| |
| | Maplin usually have some that are fairly inexpensive.
| |
| |I bought one of those about 12 months ago and it is perfect for winding
| |up the landlord of my local real ale pub. The one thing he hates is to
| |be told that is serving his beer at the wrong temperature. A quick pull
| |of the trigger and he is convinced.
|
| Surely it measured the temperature of the outside of the glass not the
| temperature of the beer ;-)

I would use my probe thermometer

|LOL Yes. But since the glass is only a container that is quite thin, the
|contents will be equal to the outside of the glass.

Glass is far from a perfect conductor of heat so the outside surface glass
will be higher than the beer.

As I *hate* beer, this is just of casual interest.
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

crb wrote:
Andrew Gabriel wrote:
No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.


Clouds at -40 to -50? - I don't think so. You have to go to around
30,000 feet or above to get down to those temperatures.

CRB

Sea level standard is ISA 15 deg. C and a lapse rate of 1. 98 deg. per
1000' you can work it out for yourself? Although in different parts of
the world the altitude temp does not always follow the formulae.

The message .com
from "jaycee" contains these words:


crb wrote:
Andrew Gabriel wrote:
No, I get believable readings from clouds, typically -40 to -50,
which agrees with what aircraft report as the outside temperature.


Clouds at -40 to -50? - I don't think so. You have to go to around
30,000 feet or above to get down to those temperatures.

CRB

Sea level standard is ISA 15 deg. C and a lapse rate of 1. 98 deg. per
1000' you can work it out for yourself? Although in different parts of
the world the altitude temp does not always follow the formulae.

The adiabatic temperature drop I remember from my school days more than
40 years ago was 3 degrees per thousand feet.

A quick google led me to Wikipedia (I wonder why:-)) and an article that
purported to explain the differences between Environmental lapse rate
(1.99 degrees C/1000 ft), Dry adiabatic lapse rate (3/1000) and Moist
adiabatic lapse rate (1.51/1000).

ISTM that on the basis of that article 3 degrees per thousand feet
should be the figure to use to determine the temperature drop between
ground and cloud.

--
Roger Chapman

On 18 Oct 2006 01:47:36 -0700, "jaycee"
wrote:

|
|crb wrote:
| Andrew Gabriel wrote:
| No, I get believable readings from clouds, typically -40 to -50,
| which agrees with what aircraft report as the outside temperature.
|
|
| Clouds at -40 to -50? - I don't think so. You have to go to around
| 30,000 feet or above to get down to those temperatures.
|
| CRB
|
|Sea level standard is ISA 15 deg. C and a lapse rate of 1. 98 deg. per
|1000' you can work it out for yourself? Although in different parts of
|the world the altitude temp does not always follow the formulae.

I would believe -40C to -50C the IR thermometer might not *see* the clouds,
but something else far higher.
--
Dave Fawthrop dave hyphenologist co uk Google Groups is IME the *worst*
method of accessing usenet. GG subscribers would be well advised get a
newsreader, say Agent, and a newsserver, say news.individual.net. These
will allow them: to see only *new* posts, a killfile, and other goodies.

The message
from Dave Fawthrop contains these words:

I would believe -40C to -50C the IR thermometer might not *see* the clouds,
but something else far higher.

If anyone remembers Daedalus and Dreadco in the back of New Scientist
many moons ago, the author suggests using reflectors to radiate heat
into the blackness of space, since at night it's a nice low temperature
- perfect for the cold end of a heat engine using solar stored from the
previous day as the hot end.
Not an entirely stupid idea.

--
Skipweasel
Pay no attention to that man behind the curtain.