IR Thermometer
bill horne
I'm now the proud possessor of a Radio Shack IR Thermometer
(no-contact). After playing with it for a few hours, I'm satisfied with
it, and think that reports of its gross inaccuracies may be incorrect.
If I stand in the middle of a room, and point it around here and there -
walls, floor, ceiling - it reads within 2 degrees of of another
thermometer in the room.
If I point it at a glass of ice and water, it reads the same as a
thermometer in the glass.
If I go outside (night), and point it horizontally - or a little less
than horizontally - at the woods, it reads within 2 degrees of a
thermometer that I'm waving around in the other hand. The sky is damned
cold, though.
If I point it into my van, it reads within 2 degrees of a thermometer in
the van.
A partially melted piece of ice reads 29 degrees.
The surface temp of my thumb and forefinger is 95 degrees. A thermometer
held between them reads 94 degrees.
I'm happy. And impressed - particularly with the
pointing-it-at-the-woods part.
--
bill
Theory don't mean squat if it don't work.
Lee Bray
I did basically the same and was well satisfied with the results. I mean if
there is a large disparity in the temperatures of my dualies then I will know I
have a low tire. Neat to check out the freezer and stuff also. I think that it
is a good tool as long as it is understood that it is not accurate to the
decimal point. I like mine and will be using it on the road. Have not tried
checking the temperatures in the MH refrigerator which was another important
reason I bought it. I probably had mine set to low/high trying to be sure it
was keeping stuff frozen or cool.
--
Lee (aka Jerry) Jax/Fl
SFC USA Retired, and Retired Civilian
It is tough being a Sexy Motor Homing Senior Citizens
Web Page: http://home.comcast.net/~l.bray/
"bill horne" <red...@rye.net> wrote in message
GBinNC
wrote:
>Have not tried
>checking the temperatures in the MH refrigerator which was another important
>reason I bought it.
I have the feeling bill won't be needing his for that. It may not
register that high anyway...
(Sorry, bill. No I'm not. <g>)
GB in NC
Jon Porter
> The wife went to Warner Robins today, so I gave her a honeyget list, and
> I'm now the proud possessor of a Radio Shack IR Thermometer
> (no-contact). After playing with it for a few hours, I'm satisfied with
> it, and think that reports of its gross inaccuracies may be incorrect.
You have done some of the same "tests" that I did:
> If I stand in the middle of a room, and point it around here and there -
> walls, floor, ceiling - it reads within 2 degrees of of another
> thermometer in the room.
I have found the readings indoors to be spot on. The thermometer that I
check it against is a professional quick read model that is adjustable using
either ice water (preferred method) or boiling water to set it.
> If I point it at a glass of ice and water, it reads the same as a
> thermometer in the glass.
>
> If I go outside (night), and point it horizontally - or a little less
> than horizontally - at the woods, it reads within 2 degrees of a
> thermometer that I'm waving around in the other hand. The sky is damned
> cold, though.
>
> The surface temp of my thumb and forefinger is 95 degrees. A thermometer
> held between them reads 94 degrees.
I got 96 degrees. Either I'm a hot guy, or you're just a little cooler than
I am.
> I'm happy. And impressed - particularly with the
> pointing-it-at-the-woods part.
Ditto. Useful little gadget, isn't it?
bill horne
And I'm sorry that I can no longer respond satisfyingly to your dipping
my pigtail into the inkwell. Since it's unlikely that my TT will ever be
put into service again, it's not on my list of things to get excited
about. I'm a full-up minimalist flatspotter now, and my list contains
things like running out of Dogs in a dry county, and coons stealing my
dogs.
One thing I'm going to use the IR thermometer for is to measure the
temperature of beer offered to me by strangers. As the old saying goes,
"Beware of strangers bearing warm beer" - or something like that.
GBinNC
wrote:
>And I'm sorry that I can no longer respond satisfyingly to your dipping
>my pigtail into the inkwell.
Well, heck. There goes my fun.
>One thing I'm going to use the IR thermometer for is to measure the
>temperature of beer offered to me by strangers. As the old saying goes,
>"Beware of strangers bearing warm beer" - or something like that.
Yeah, I've heard something like that. If I ever see you to offer you
some, it will probably be at about 30 F. (And I haven't forgotten I
owe you a six-pack.)
BTW, the other day the stonemason working on our carriagehouse had an
old diagonal metal "Red Dog" sign he had found in a junk pile and had
rescued to give to a buddy of his who is a collector of beer
paraphernalia.
I tried to talk him out of it for you but was unsuccessful. Sorry.
GB in NC
bill horne
> Yeah, I've heard something like that. If I ever see you to offer you
> some, it will probably be at about 30 F. (And I haven't forgotten I
> owe you a six-pack.)
Having not forgotten it, and actually paying the debt are two different
things. But I had forgotten it. Dipole orientation deterioration, I
guess.
> BTW, the other day the stonemason working on our carriagehouse had an
> old diagonal metal "Red Dog" sign he had found in a junk pile and had
> rescued to give to a buddy of his who is a collector of beer
> paraphernalia.
>
> I tried to talk him out of it for you but was unsuccessful. Sorry.
Thanks for trying. The effort is worth a Dog - reduce the 6pak to a
5pak.
I have a number of Dog thingys - not including the hundreds of bottle
caps that I still don't know why I'm saving.
> GB in NC
GBinNC
wrote:
>GBinNC wrote:
>
>> Yeah, I've heard something like that. If I ever see you to offer you
>> some, it will probably be at about 30 F. (And I haven't forgotten I
>> owe you a six-pack.)
>Having not forgotten it, and actually paying the debt are two different
>things. But I had forgotten it. Dipole orientation deterioration, I
>guess.
I have every intention of paying it the first time I see you, wherever
and whenever that is. I pay my debts, and I never forget one.
GB in NC
bill horne
> I have every intention of paying it the first time I see you, wherever
> and whenever that is. I pay my debts, and I never forget one.
>
> GB in NC
I note that you conspicuously made no estimate of where or when that
might be.
Have to read your output very carefully, and several times.
But if I get really concerned about it, I'll hunt you down and brandish
my Red Dog mug at you.
Carl A.
I had expected you to comment on the "never"
Too much like "all mall pet stores."
Let's check with GB thirty years from now (if we can remember) to see
whether he remembers all his then open debts.
--
Carl A. in FL
Enjoy photo-journals of my travels at
http://sky.prohosting.com/chainfl/index.htm
GBinNC
wrote:
>> I have every intention of paying it the first time I see you, wherever
>> and whenever that is. I pay my debts, and I never forget one.
>>
>> GB in NC
>I note that you conspicuously made no estimate of where or when that
>might be.
>
>But if I get really concerned about it, I'll hunt you down and brandish
>my Red Dog mug at you.
Give me some notice when you're coming and I'll have it ready. Or if I
come down 117S out of Eastman and get near Five Points, I'll bring it
by.
GB in NC
GBinNC
wrote:
>> > I have every intention of paying it the first time I see you, wherever
>> > and whenever that is. I pay my debts, and I never forget one.
>> >
>> > GB in NC
>> I note that you conspicuously made no estimate of where or when that
>> might be.
>>
>> Have to read your output very carefully, and several times.
>>
>> But if I get really concerned about it, I'll hunt you down and brandish
>> my Red Dog mug at you.
>>
>> --
>> bill
>Let's check with GB thirty years from now (if we can remember) to see
>whether he remembers all his then open debts.
It's not that hard to do. That's the only unpaid debt I have.
It's really easy to create a balance sheet: Assets on one side, a
6-pack of Red Dogs to bill on the other.
GB in NC
bill horne
> I had expected you to comment on the "never"
> --
> Carl A. in FL
I thought about it, but if he challenged me, I'd be unable to credibly
support such a claim.
And as I said, you have to read his output carefully. He did Not say, "I
pay All my debts...", and regardless of what the entire statement
implies, the absence of "all" at that location is a potential escape
hatch for a man of his exceptional wordsmithing skills.
Note that he also said, "I have every intention of...". He did Not say
the simpler, more direct, and less ambiguous, "I will..."
But at least he didn't say it in Spanish or Latin or - Gaaaakkkk -
French.
bill horne
5pak there, sonny. I want only what I deserve, earn, or win - no more,
no less.
Sometimes I keep what I find, though. Keep your excess Dogs on a short
leash.
bill horne
There's all that carefully crafted qualification stuff again. Why not
just say, "The next time I get near Eastman, I'll bring it by"?
We can argue later about how many feet "near" means. And about whether
"Eastman" means "within the city limits" or "the town center".
And I hope there's no problem agreeing that "it" means "5 Dogs". I was
also going to mention that "them" would be better than "it", but a 6pak
is an "it", and you may not have yet received and processed the
adjustment to the debt.
Pete Dumbleton
> news:40497D4B...@rye.net...
> > The wife went to Warner Robins today, so I gave her a honeyget list, and
> > I'm now the proud possessor of a Radio Shack IR Thermometer
> > (no-contact). After playing with it for a few hours, I'm satisfied with
> > it, and think that reports of its gross inaccuracies may be incorrect.
>
I don't have a check thermometer, but when I try skin readings I only
get about 90-91F whether I am shooting my arm or inside my ear.
Readings on boiling water are way low, 140-160F. Might just be my
particular unit.
I keep it on the dash, so it gets cold overnite sometimes, in which
case I find I need to warm it up before it works. One time it got
very wet in my pocket in the rain, started acting strangely and then
quit. When it dried out, it was back to its usual self.
bill horne
>
> I don't have a check thermometer, but when I try skin readings I only
> get about 90-91F whether I am shooting my arm or inside my ear.
> Readings on boiling water are way low, 140-160F. Might just be my
> particular unit.
My arm is currently at 89. Last night it was at 93 (I think). Four
readings with it stuck in my ear tonight varied between 98.5 and 100.
------------------------------------------
Skin temperature depends on air temperature and time spent in that
environment. Such weather factors as wind chill and humidity cause
changes in skin temperature. The normal temperature of skin is about 33
°C or 91 °F.
-----------------------------------------
http://hypertextbook.com/facts/2001/AbantyFarzana.shtml
So the skin reading is probably right. I don't know what your ear
problem is. Are you stuffing the thing right in the hole? I am - just
prior to the Ouch Point.
Notice to consenting adults: Do not try this at home on your rectum
without supervision.
> I keep it on the dash, so it gets cold overnite sometimes, in which
> case I find I need to warm it up before it works.
The (Gasp!) manual says:
------------------------------------------------
Cautions:
- Protect the thermometer from "thermal shock", caused by large or
abrupt ambient temperature changes. Allow 30 minutes for the thermometer
to stabilize before use when exposed to large temperature swings.
- Do not leave the thermometer on or near hot objects.
---------------------------------------------------
> One time it got
> very wet in my pocket in the rain, started acting strangely and then
> quit. When it dried out, it was back to its usual self.
The manual also says:
------------------------------------------
CARE
Keep the thermometer dry; if it gets wet, wipe it dry immediately. Use
and store the thermometer only in normal temperature environments.
------------------------------------------
It says some other things worth reading, too.
bill horne
(black) skillet. Readings were the same in both - about 200 when pointed
at a non-bubbling spot, and about 210 on a bubbling spot (about 2" from
the surface o both). That's close enough for me, since I'm at 300 ft,
and I didn't check baro pressure.
Jon Porter
"Pete Dumbleton" <ratatou...@yahoo.com> wrote in message
news:a9a814de.04030...@posting.google.com...
>
> I don't have a check thermometer, but when I try skin readings I only
> get about 90-91F whether I am shooting my arm or inside my ear.
> Readings on boiling water are way low, 140-160F. Might just be my
> particular unit.
With boiling water it is getting the temperature of the steam. The R-Shack
model is not that sophisticated to deal with steam, although there are
specialty models for the food industry that can. At a price of course.
bill horne
My RS model reads 210 pointing at bubbles, and 200 not pointing at
bubbles. What is it reading?
Pete Dumbleton
Considering the abuse I subject it to, it seems to be a pretty tuff
little gizmo. The time it got wet, it wouldn't have been much wetter
if I'd submerged it...
However, the reason I got it is primarily to check relative tire and
hub temps and it clearly does a good job of that. Skin and water
temps are not really of much significance.
bill horne <red...@rye.net> wrote in message news:<404AB943...@rye.net>...
Flo Cala
news:a9a814de.04030...@posting.google.com...
> hub temps and it clearly does a good job of that. Skin and water
> temps are not really of much significance.
I tried the $19.95 IR Thermometer in Radio Shack today. DH and I
registered 91º, and the young salesman, just off lunch break in the
back room, was 83º. I touched his arm, and his skin felt cold.
What is a *significant difference* when it comes to a useful purpose
such as checking "relative tire and hub temps"? The humans in above
test were still -- well... humans, and not ready to kick the bucket
(yet). Also, wouldn't one have to do varying tests and log the speed,
weather, distance, etc. in order to have a guide as to how the tires
react under varying conditions?
--
Dot
bill horne
>
> Stick it in your ear 'til it hurts? Hmm...
I said, "...just prior to the Ouch Point".
"prior", not "at".
'Course, to do that right the first time, you have to be very familiar
with your ear - and I've had mine for 62 years. It also helps if you've
had friends throughout your life who weren't hesitant to say, "Stick it
in yer ear, horne".
> Considering the abuse I subject it to, it seems to be a pretty tuff
> little gizmo. The time it got wet, it wouldn't have been much wetter
> if I'd submerged it...
>
> However, the reason I got it is primarily to check relative tire and
> hub temps and it clearly does a good job of that. Skin and water
> temps are not really of much significance.
Well, mine seems to be doing a great job on just about everything, and
there's nothing "relative" about it - it's damned close.
And there seems to be something to this skin temp thing. It's cooling
down here, and off and on tonight, I've been randomly chilly and not
chilly. When I felt a little chilly, I'd zap my arm - below 91 every
time. When I wasn't chilly, and happened to think about it, I'd zap my
arm - above 91 every time.
I'm probably gonna run the battery down before I ever actually Need the
thing.
I just went outside and zapped the woods again. Phaser says 46,
thermometer says 49. Suits me.
Damn. I love it when a gadget performs better than I expect it to.
Hey, Neon, I owe you a Dog. If you hadn't confused me at first, I'd
spring for 2.
bill horne
> I tried the $19.95 IR Thermometer in Radio Shack today.
Damn. I paid 29.99 for mine - and that was supposed to be 10 bucks off.
> DH and I
> registered 91º, and the young salesman, just off lunch break in the
> back room, was 83º. I touched his arm, and his skin felt cold.
>
> What is a *significant difference* when it comes to a useful purpose
> such as checking "relative tire and hub temps"? The humans in above
> test were still -- well... humans, and not ready to kick the bucket
> (yet). Also, wouldn't one have to do varying tests and log the speed,
> weather, distance, etc. in order to have a guide as to how the tires
> react under varying conditions?
> --
> Dot
Yes, and until you gain either personal experience with your own tires,
or find some blurb about it on the web, I think it'll be safe to assume
you have something that needs checking if one tire is significantly
hotter "relative" to the others.
Lee Bray
Just a difference in one tire could indicate a low tire, I am not sure yet
what constitutes a good indicator but I would be suspicious of say 3º to 5º or
more. Lot easier and faster than pulling out the tire pressure gauge and
checking each individual tire pressure! Also would be a good indicator if your
refrigerator in the MH is working properly. I did the one in the house and
found the temperatures to be lower than necessary, a slight adjustment and later
checks may save a few cents on the electricity bill. Also while playing around
I checked a 60 watt light bulb giving off 135º and a fluorescent 90.5º after
letting it warm up which I did not do on the 60 watt bulb. I think I can find
enough things to use it on to justify me buying the toy! (grin) Now I think I
will go to Sam's and buy some of those fluorescent lights that screw in. Not
only will it save electricity but will cut down on the heat production that I
have to turn around and cool in the summer.
But then this is just my opinion.
--
Lee (aka Jerry) Jax/Fl
SFC USA Retired, and Retired Civilian
It is tough being a Sexy Motor Homing Senior Citizens
Web Page: http://home.comcast.net/~l.bray/
"Flo Cala" <floREM...@earthlink.net> wrote in message
news:c2h1b3$1sst78$1...@ID-186277.news.uni-berlin.de...
Bob Hatch
news:q66p40ld473t1o167...@4ax.com...
>
> I have been using one of these thermometers for at least six months now.
> The differences between tire temps are always much greater than that.
> Immediately after pulling off the freeway, tires may read from 65
> degrees on the rear shady side of the toad on a cold day, up to 130
> degrees on the inside dually sunny side on a hot day.
>
> The inside duallies are hotter than the outside duallies. The tires on
> the sunny side are hotter than the tires on the shady side. The front
> tires on the toad are hotter than the rear tires. All the tires are
> hotter on hot days and at high speeds.
>
> What I am looking for is an unexpected differential of 20 degrees or
> more. Anything else seems to be normal variation.
Dave, do you mean 20 degrees differential from the outside dual to the
inside dual on the same side, or 20 degrees from the outside dual on onside
to the outside dual on the other side?
--
Everyday I beat my own previous record for number
of consecutive days I have stayed alive.
http://www.bobhatch.com
bill horne
> I checked a 60 watt light bulb giving off 135º and a fluorescent 90.5º after
> letting it warm up which I did not do on the 60 watt bulb. I think I can find
> enough things to use it on to justify me buying the toy! (grin) Now I think I
> will go to Sam's and buy some of those fluorescent lights that screw in. Not
> only will it save electricity but will cut down on the heat production that I
> have to turn around and cool in the summer.
FYI, I get around 150 on the side a screw-in 20W flourescent pointing
down, around 160 on the side of a 60W bulb pointing up, and around 250
on the top of a 60W bulb pointing up. If I zap near the base - the base
is pointing up - of the flourescent, I get around 200.
Lee Bray
I just did not wait for either to get to their full heat
level. Sounds as if you have more time than I (grin)
--
Lee "bill horne" <red...@rye.net> wrote in message
Peter Pan
Lee Bray wrote:
How far away from the bulbs are you? To be PC we should probably standardize
on distance. I'm playing with mine on the lights here, and the closer I get,
the more the temp goes up.
PS here is a weird one for ya, my LCD screen TV shows 90, and my CRT TV
shows as 83 (and the projection LCD TV shows 72).
I always thought LCD screens were cooler than CRT's...
Jon Porter
My guess is bubbles and not bubbles. My hunch is that there might be a
difference in how far you are holding the unit away from what you are taking
the temp of compared to Pete. Distance can make a difference in the
readings.
Just for fun this evening, I was outside and took a reading pointed straight
at the ground, straight up, and parallel to the ground. The down temp was
49, the up temp was 16, and the horizontal temp was 36, which was what the
local Weatherbug station reports. I'm really puzzled by the up reading.
Perhaps it was because of the partly stormy weather we had.
bill horne
> How far away from the bulbs are you? To be PC we should probably standardize
> on distance. I'm playing with mine on the lights here, and the closer I get,
> the more the temp goes up.
About 2-3 inches.
And I ran into the abrupt temperature change problem last night. I went
out to try to repeat the previous nights results, and I got
not-believable results from van body, tires, and woods - off by 20-30
degrees. So I left it outside for about 30 minutes, and tried again -
back within 2-3 degrees of another thermometer.
The manual apparently means what it says - that the device itself must
be cooled or warmed to near-ambient temp before it'll read correctly.
And no, I don't know what "near" means yet - but I know that going from
a 75 deg house to a 40 deg yard is way too much for it to handle.
A quick web crawl indicates that this true of even more expensive ones -
until they get expensive enough to have some form of ambient temp
compensation.
bill horne
>
> "bill horne" <red...@rye.net> wrote in message
> news:404BB7F4...@rye.net...
> > Jon Porter wrote:
> > >
> > > "Pete Dumbleton" <ratatou...@yahoo.com> wrote in message
> > > news:a9a814de.04030...@posting.google.com...
> > > >
> > > > I don't have a check thermometer, but when I try skin readings I only
> > > > get about 90-91F whether I am shooting my arm or inside my ear.
> > > > Readings on boiling water are way low, 140-160F. Might just be my
> > > > particular unit.
> > >
> > > With boiling water it is getting the temperature of the steam. The
> R-Shack
> > > model is not that sophisticated to deal with steam, although there are
> > > specialty models for the food industry that can. At a price of course.
> >
> > My RS model reads 210 pointing at bubbles, and 200 not pointing at
> > bubbles. What is it reading?
>
> My guess is bubbles and not bubbles. My hunch is that there might be a
> difference in how far you are holding the unit away from what you are taking
> the temp of compared to Pete. Distance can make a difference in the
> readings.
Right. Hold it close enough, and you can read bubbles OR no bubbles.
Move it back enough and you read bubbles AND no bubbles. As long as Pete
had the spot size smaller than the pot, though, it should have been up
around the right temp. Unless he violated the ambient temp thing.
> Just for fun this evening, I was outside and took a reading pointed straight
> at the ground, straight up, and parallel to the ground. The down temp was
> 49, the up temp was 16, and the horizontal temp was 36, which was what the
> local Weatherbug station reports. I'm really puzzled by the up reading.
> Perhaps it was because of the partly stormy weather we had.
Last night was a clear sky here, and the phaser bottomed out with a "- -
-" on the display when pointed up. The previous night was cloudy, and I
was getting minus readings - although the manual says the range is
0-400.
Neon John
substrate (background, reference junction) temperature and the temperature on
the microthermopiles inside. The sensor is therefore temperature compensated
by means of some sort of sensor, usually a diode, mounted near or in contact
with the pyrometer sensor. It takes awhile for the change in ambient
temperature to filter through to the diode sensor while the thermopiles sence
the change in radiation immediately. Only when the two are again equal will
the compensation be correct.
Fancy ones like my Wahl have a "zero" function in which one half-pulls the
trigger which raises a black target in front of the pyrometer sensor. The
processor logs that as "zero". A complete pull on the trigger moves the flag
past the sensor and opens the optical path from the infrared telescope,
enabling a reading.
Even on the fancy one, a zero'ing is necessary every few minutes after a big
ambient temperature change, until the instrument temperature equilibrates with
the new ambient.
---
John De Armond
johngdDO...@bellsouth.net
http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN
Flo Cala
Yes, and until you gain either personal experience with your own
tires,
or find some blurb about it on the web, I think it'll be safe to
assume
you have something that needs checking if one tire is significantly
hotter "relative" to the others.
--
bill
Theory don't mean squat if it don't work.
Hmmm... I see in your other posts that you are experimenting with how
hot things get. I understand that can become an obsession as a man
ages. <g>
How much is significant difference between tires under what
conditions. Maybe it's like the "age of consent"? <g> The IR
thermometer seems like a nice toy that may or may not have a
scientific or practical use -- for which conditions would have to be
controlled. But I like toys, too, although I'll stick with the thumper
for the tires since we seldom travel far nowadays.
--
Dot
bill horne
>
> The pyrometer sensor generates an output proportional to the difference in its
> substrate (background, reference junction) temperature and the temperature on
> the microthermopiles inside. The sensor is therefore temperature compensated
> by means of some sort of sensor, usually a diode, mounted near or in contact
> with the pyrometer sensor. It takes awhile for the change in ambient
> temperature to filter through to the diode sensor while the thermopiles sence
> the change in radiation immediately. Only when the two are again equal will
> the compensation be correct.
>
> John De Armond
Does that mean that swinging the thing eyehole forward through the air
might make it ready sooner?
bill horne
>
> "bill horne" <red...@rye.net> wrote in message
> news:404C3C7C...@rye.net...
> Yes, and until you gain either personal experience with your own
> tires,
> or find some blurb about it on the web, I think it'll be safe to
> assume
> you have something that needs checking if one tire is significantly
> hotter "relative" to the others.
>
> --
> bill
> Theory don't mean squat if it don't work.
>
> Hmmm... I see in your other posts that you are experimenting with how
> hot things get. I understand that can become an obsession as a man
> ages. <g>
>
> How much is significant difference between tires under what
> conditions.
I don't have a clue. Yet.
> Maybe it's like the "age of consent"? <g> The IR
> thermometer seems like a nice toy that may or may not have a
> scientific or practical use -- for which conditions would have to be
> controlled. But I like toys, too, although I'll stick with the thumper
> for the tires since we seldom travel far nowadays.
> --
> Dot
So you asked the question because...?
Neon John
I'd been looking for an excuse. :-) Since a picture is worth a thousand
words:
http://bellsouthpwp.net/j/o/johngd/files/Radio_Shack_IR_thermometer/Internals.jpg
A shot of the internals. First thing I notice is the Raytek logo. This is
super very good stuff! Raytek and Wahl are the Big Two in the IR thermometry
field. No wonder the thing works so well. To the right is the pyrometer
attached to an isothermal mass. This mass does two things: It slows the
change in temperature the pyrometer sees and it provides the pyrometer a nice
even thermal background. Note that the pyrometer is a 4 lead device. More on
that later.
http://bellsouthpwp.net/j/o/johngd/files/Radio_Shack_IR_thermometer/pyrometer_detail.jpg
Here is the pyrometer removed from the isothermal block. Looks like a zinc
selenide unit. I paid several hundred $$$ for a bare sensor perhaps 5 years
ago. Yeah for Moore's Law!!
http://bellsouthpwp.net/j/o/johngd/files/Radio_Shack_IR_thermometer/PCB%20back.jpg
Back side of the PCB showing several switches and connectors. The LCD
interface is to note. IT connects to the LCD display via a conductive rubber
strip. If your thermometer starts dropping segments or gets dim, take the
unit apart, clean these contacts with PGA, dry and reassemble. Do not touch
the conductive rubber unless absolutely necessary. I've never had much luck
getting the thing to conduct after molesting one.
http://bellsouthpwp.net/j/o/johngd/files/Radio_Shack_IR_thermometer/fresnel%20lens.jpg
This is one of the most important feature and what sets this unit apart from
the other cheap ones. An infrared Fresnel lens that focuses the field onto
the pyrometer. Most of the cheap units I've seen have no lens and simply
expose the pyrometer sensor to the world. With no focus, the sensor responds
to everything in the field of view. This lens narrows the field of view and
screens off-axis IR radiation.
Now to your question, Bill. The 4 leads emitting from the pyrometer device
indicates one of two things to me. I'm not sure which, as I haven't kept up
with this field in a couple of years. One possibility is that the temperature
compensation sensor is built in the pyrometer package. The other possibility
is that the sensor can be electronically "blinded" so that it can read its own
temperature.
In either event, the actual pyrometer package is where the reference
temperature is measured. The package is contained within that isothermal
metal block. Ergo, the whole block must reach the new ambient before the unit
will indicate accurately again.
Swinging the unit hole forward would indeed help, as the isothermal block
extends to the face of the unit. Drilling some small vent holes in the case
near the sensor would also help, at the loss of some amount of water
resistance.
Seeing how well this thing is designed I think I'm going to go snarf up the
remaining stock at my local Rat Shack :-)
John
---
bill horne
> Swinging the unit hole forward would indeed help, as the isothermal block
> extends to the face of the unit. Drilling some small vent holes in the case
> near the sensor would also help, at the loss of some amount of water
> resistance.
>
> Seeing how well this thing is designed I think I'm going to go snarf up the
> remaining stock at my local Rat Shack :-)
>
> John
Thanks, John. I knew you'd come through. And before you lose your
momentum, here's one more:
Is there a table, chart, graph, formula or something for this thing, so
that I could adjust it on the fly by adding or subtracting a number
based on the difference between ambient and phaser temp?
For example, say that I know the the temp of the phaser because it's
been riding in the van with me, and I know the temp in the van. I either
know - or can measure with a regular thermometer - the outside temp. So
I'm busting down the road and decide to stop and check my tires - and I
don't want to wait 30 minutes. it's 75 in the van, and 35 outside. I
stop, jump out, zap a tire, and get a not-believable reading. Then I
apply the magic fudge factor to the reading, and get a much more
accurate reading. Possible? Oh. Sorry. That makes it two more questions.
Kind of ironic that this thing can measure a temp in half a second, but
you might have to wait 30 minutes for it to get its ducks lined up if
you don't plan ahead.
Lone Haranguer
> Kind of ironic that this thing can measure a temp in half a second, but
> you might have to wait 30 minutes for it to get its ducks lined up if
> you don't plan ahead.
>
LZ (ducking behind something sturdy)
Pete Dumbleton
on the dash, Bill) whenever I stop and walking a circle around the rig
shooting tires and hubs as I go. After a while, you get a feel for
what they should be in varying conditions (even which side is in the
sun sometimes makes a difference), sort of a home-built data base.
But what's really important is not so much the absolute number as it
is the variation between objects - If I were to see a 20 degree
difference between the rolling things on my rig, something is likely
amiss! Example, if all my tires are at 90-95, the road is hot, the
ambients are hot, etc., then all is OK. But if one of my tires is at
95 and the others are at 70-75, and it's raining and chilly...
Likewise, most of the stuf under the hood (except exhaust system of
course) will be pretty close to each other under normal
circumstances).
"Flo Cala" <floREM...@earthlink.net> wrote in message news:<c2h1b3$1sst78$1...@ID-186277.news.uni-berlin.de>...
Flo Cala
news:a9a814de.04030...@posting.google.com...
it's
> on the dash, Bill) whenever I stop and walking a circle around the
rig
> shooting tires and hubs as I go. After a while, you get a feel for
> what they should be in varying conditions (even which side is in the
> sun sometimes makes a difference), sort of a home-built data base.
>
> But what's really important is not so much the absolute number as it
> is the variation between objects - If I were to see a 20 degree
> difference between the rolling things on my rig, something is likely
> amiss! Example, if all my tires are at 90-95, the road is hot, the
> ambients are hot, etc., then all is OK. But if one of my tires is
at
> 95 and the others are at 70-75, and it's raining and chilly...
>
> course) will be pretty close to each other under normal
> circumstances).
Good answer, Pete. Thanks. Though I'd keep an IRT off the dash and
away from the heater or AC. Presumably, a difference in tires of 10 or
more degrees would indicate trouble.
--
Dot
Neon John
equilibrated to the van's temperature, at the instant you step outside, you
should be able to just add or subtract (depending on which way the temperature
is inside vs out) the difference between inside and out. If this works it
would only work for a few seconds, as the pyrometer chip immediately starts
cooling or heating as the case may be via IR radiation.
This problem exists even on my fancy unit. If I aim it at something fairly
hot, the IR radiation will heat up the sensor more rapidly than the
compensation can work. With an open shutter, this constitutes itself as long
term (minutes) drift. Similarly, if I take it outside into the cold, the
sensor cools by radiation faster than the heat can be pulled from the
compensation sensor. It drifts down. The only solution I've found is to
half-trigger and zero immediately before each reading. This thing has a
1mv/deg analog output but the drift renders it useless for long term data
logging. My unit is >10 years old so maybe they've improved things in later
models.
For a really fancy one, check this one out:
http://bellsouthpwp.net/j/o/johngd/files/misc/raygun.jpg
This is a hand-held reflector telescope with a pyrometer sensor mounted in the
focus. Also a Raytek product. The rifle scope aims coaxially with the
telescope via a periscope arrangement. No parallax error. As long as the
target can fill the little square in the cross-hairs, the instrument can read
the temperature, regardless of the distance. One can measure an individual
wire clamp on an overhead transmission line, even on the next block! This
instrument addresses the problem you're having the old fashioned way - it
reads in degrees above ambient and has a little mercury thermometer to show
ambient temperature. One does the math in his head :-)
BTW, you ought to see the looks I get as I walk along a street looking at the
overhead lines while holding the raygun out and up like a rifle...
John
---
bill horne
>
> I can't imagine any universal formula. Assuming the instrument had
> equilibrated to the van's temperature, at the instant you step outside, you
> should be able to just add or subtract (depending on which way the temperature
> is inside vs out) the difference between inside and out. If this works it
> would only work for a few seconds, as the pyrometer chip immediately starts
> cooling or heating as the case may be via IR radiation.
> John De Armond
Regardless of your first sentence, that's my kind of Universal Formula.
It's simple, requires only haste and minimal math abilities, and is
intuitively obvious - although it could be problematic for those of us
who are getting old, slow of body and mind, and weak in the tuits.
But it may serve most of my purposes. I'll test it. Eventually.
Thanks again - if it turns out to work.
bill horne
>
> What I do is just be in the habit of grabbing the IRT (that's why it's
> on the dash, Bill) whenever I stop and walking a circle around the rig
> shooting tires and hubs as I go. After a while, you get a feel for
> what they should be in varying conditions (even which side is in the
> sun sometimes makes a difference), sort of a home-built data base.
I understand, but I'm - like Flo Cala - going to keep mine out of the
sun to eliminate one varible and to facilitate my never-ending quest for
cheap accuracy.
Bob Giddings
wrote:
>GBinNC wrote:
>
>> Yeah, I've heard something like that. If I ever see you to offer you
>> some, it will probably be at about 30 F. (And I haven't forgotten I
>> owe you a six-pack.)
>
>Having not forgotten it, and actually paying the debt are two different
>things. But I had forgotten it. Dipole orientation deterioration, I
>guess.
>
>> BTW, the other day the stonemason working on our carriagehouse had an
>> old diagonal metal "Red Dog" sign he had found in a junk pile and had
>> rescued to give to a buddy of his who is a collector of beer
>> paraphernalia.
>>
>> I tried to talk him out of it for you but was unsuccessful. Sorry.
>
>Thanks for trying. The effort is worth a Dog - reduce the 6pak to a
>5pak.
>
>I have a number of Dog thingys - not including the hundreds of bottle
>caps that I still don't know why I'm saving.
>
>> GB in NC
They'd make good shrapnel if you ever turn terrorist. Unfortunately
they'd easily be traced back to you.
www.arcatapet.net/bobgiddings
Current email at:
bobgiddings0 at yahoo dot com
Bob Giddings
wrote:
>The wife went to Warner Robins today, so I gave her a honeyget list, and
>I'm now the proud possessor of a Radio Shack IR Thermometer
>(no-contact). After playing with it for a few hours, I'm satisfied with
>it, and think that reports of its gross inaccuracies may be incorrect.
>
>If I stand in the middle of a room, and point it around here and there -
>walls, floor, ceiling - it reads within 2 degrees of of another
>thermometer in the room.
>
>If I point it at a glass of ice and water, it reads the same as a
>thermometer in the glass.
>
>If I go outside (night), and point it horizontally - or a little less
>than horizontally - at the woods, it reads within 2 degrees of a
>thermometer that I'm waving around in the other hand. The sky is damned
>cold, though.
>
>If I point it into my van, it reads within 2 degrees of a thermometer in
>the van.
>
>A partially melted piece of ice reads 29 degrees.
>
>The surface temp of my thumb and forefinger is 95 degrees. A thermometer
>held between them reads 94 degrees.
>
>I'm happy. And impressed - particularly with the
>pointing-it-at-the-woods part.
Durn it. I was almost in my budget this month, despite an orgy of
book buying. Now I gotta have one of these gadgets.
With Bush about to unleash 200 million bucks worth of TV advertising,
I may need it as a rhetoric checker. Just point it at the TV when
things seem to be getting overheated?? Hmm. 'Course this is only a
(gasp) theory.
There's even a waitress I'd like to point it at, at the risk of being
understood. Nah. It probably doesn't read that high.
Bob, off to the Radio Shack
Chris Bryant
> There's even a waitress I'd like to point it at, at the risk of being
> understood.
I remember a great book titled "Some Birds Don't Fly", where they adjusted
a heat seeking missile to lock on to 98.6° and set it outside the
secretarial pool (they were just watching the gimbaled nose of the thing).
--
Chris Bryant
http://bryantrv.com
Pete Dumbleton
Well, actually, I have one of those hold-all things that's supposed to
be on the visor, but it weights my old visor down too much, so I
'velcroed' it to the dash and the IRT lives inside it. Not directly
in the sun but not down in the shade under the seat either. Some day
soon I'll have to boil some water and try it out again when it is
temperature-stabilized. I'd try it out on my toes but am afraid that
I might get some temp variations leading to anxiety over whether my
internal pressures need adjusting, and I wouldn't want to get Will and
David excited...
bill horne
>
> Well, actually, I have one of those hold-all things that's supposed to
> be on the visor, but it weights my old visor down too much, so I
> 'velcroed' it to the dash and the IRT lives inside it. Not directly
> in the sun but not down in the shade under the seat either. Some day
> soon I'll have to boil some water and try it out again when it is
> temperature-stabilized. I'd try it out on my toes but am afraid that
> I might get some temp variations leading to anxiety over whether my
> internal pressures need adjusting, and I wouldn't want to get Will and
> David excited...
Just got back from a short camping trip, where I zapped eveything in
sight. Tentatively concluded that the the best way to get a quick,
accurate, nighttime temp is to zap the side of my van.
Seems to work fine on beer bottles (with beer inside), too - as long as
you stay off the label.
And if you don't realize it in the usual way, it'll tell you that your
hands are cold.
Lone Haranguer
>
> Just got back from a short camping trip, where I zapped eveything in
> sight. Tentatively concluded that the the best way to get a quick,
> accurate, nighttime temp is to zap the side of my van.
>
> Seems to work fine on beer bottles (with beer inside), too - as long as
> you stay off the label.
So it will tell you which is the coldest beer in the fridge? When is
your fridge going to have one of these widgets built in the door?
LZ
bill horne
> So it will tell you which is the coldest beer in the fridge?
There's a minor problem with the ambient temp thing when checking stuff
in the fridge. In my so far limited experience, it seems best to take it
out to shoot it.
> When is
> your fridge going to have one of these widgets built in the door?
> LZ
Damn. They got door widgets that'll tell you which beer in there is the
coldest? That's amazing.
Lone Haranguer
>>When is
>>your fridge going to have one of these widgets built in the door?
>>LZ
>
>
> Damn. They got door widgets that'll tell you which beer in there is the
> coldest? That's amazing.
>
I picture it being inside the door with just a hole for the sensor and
you just swipe the beer over it like a scanner. If you have beer on
various shelves you can check which are coldest before imbibing.
Hi tech is a boon to the quality of life.
LZ
bill horne
> I picture it being inside the door with just a hole for the sensor and
> you just swipe the beer over it like a scanner. If you have beer on
> various shelves you can check which are coldest before imbibing.
>
> Hi tech is a boon to the quality of life.
> LZ
I probably won't be getting one of those, because I don't keep beer in
the fridge. I don't drink much beer at home unless I have beer-drinking
company, and then I put them in a cooler with ice.
When I do occasionally want one at home, I stick it the freezer for a
while. Now that I have a phaser, I'll know when the while is up.
Lon VanOstran
>When I do occasionally want one at home, I stick it the freezer for a
>while. Now that I have a phaser, I'll know when the while is up.
>
>--
>bill
If you have any warm _cans_ of beer around, it very easy to take a can of beer
from "pee" warm to ice cold in 60 seconds or less by laying it on it's side in
a bowl of ice cubes, and slowly turning it (finger walking it) in the ice. It's
pretty amazing how well it works and how easy it is. I've won a lot of bets on
that one.
Lon
bill horne
> If you have any warm _cans_ of beer around, it very easy to take a can of beer
> from "pee" warm to ice cold in 60 seconds or less by laying it on it's side in
> a bowl of ice cubes, and slowly turning it (finger walking it) in the ice. It's
> pretty amazing how well it works and how easy it is. I've won a lot of bets on
> that one.
>
> Lon
I'm gonna test that now that I've got a way to do it. I was going to
test it the last time you mentioned it, but I never figured out how to
get the tab back on the can.
I'll have to start with a Coke, though. I don't have any cans of beer.
Tom Shaw
TSnews:405251ED...@rye.net...
bill horne
>
> It might not work with coke due to specific heat differences :-).
> TS
I've already run into a small problem with the Coke can - the phaser
doesn't read the can correctly. Once I opened it and checked it with a
dunked thermometer, I found that a piece of Scotch Magic tape on the can
does the job. Maybe I'll go to town today and buy a couple of cans of
beer.
Did you know that Dog will barely go through a tea strainer? Coke runs
right through it, though. I post this tidbit so that if anyone ever gets
gnats in their Dog, they won't waste time with a tea strainer.
bill horne
> If you have any warm _cans_ of beer around, it very easy to take a can of beer
> from "pee" warm to ice cold in 60 seconds or less by laying it on it's side in
> a bowl of ice cubes, and slowly turning it (finger walking it) in the ice. It's
> pretty amazing how well it works and how easy it is. I've won a lot of bets on
> that one.
>
> Lon
Ok, I've tested it with a Coke, and unless it works different with beer,
you wouldn't win that bet with me, because I don't consider 58 to be ice
cold.
start - 72
1 min - 58
2 min - 43
3 min - 51
I don't know where the 43 came from, but when I opened it at 3 min, and
dunked a thermometer in, it read 51 - and I don't consider that 'ice
cold', either.
Here's what I did:
Got a Coke that was sitting around, put a piece of magic tape on it, and
zapped it. A thermometer showed room temp at 72.
Put it in a bowl of ice and started finger-walking it. At 1, 2, and 3
minutes, I zapped it. After zapping at 3 min, I popped the tab and
stirred the contents with the Pyrex thermometer probe.
I'll eventually get around to testing this with a beer in a can - and in
a bottle.
Nevertheless, even if it takes 5-10 min to get it 'ice cold', the method
may have significant advantages over sticking it in the freezer or just
dropping it in the Coleman - if it works on bottles.
Lon VanOstran
>Ok, I've tested it with a Coke, and unless it works different with beer,
>you wouldn't win that bet with me, because I don't consider 58 to be ice
>cold.
I've done it hundreds of times with beer. It works. Never tried it with Coke.
Lon
Bob Giddings
wrote:
>Lon VanOstran wrote:
Perhaps you need to drink a couple of beers before you measure one, to
make it come out right.
BTW, I just zapped my RV's open freezer, and it's 14 degrees F in
there. A thermometer read 17 degrees. 32 degrees in the fridge.
Pretty cool gadget.
Bob
bill horne
> BTW, I just zapped my RV's open freezer, and it's 14 degrees F in
> there. A thermometer read 17 degrees. 32 degrees in the fridge.
> Pretty cool gadget.
>
> Bob
Yep - and I recently read that you can use it to test (quietly now) tire
pressure. You zap the middle of the tread, and the outside edges of the
tread, and they should read about the same. If the outsides are hotter,
you're underinflated for conditions, and if the middle is hotter, you're
overinflated for conditions.
I haven't tested that, though.