Post by thread:[OT]: handy gadget

Hi, anyone here got a non-contact infrared (emissive) thermomter? I got one for xmas and it's great. You can point it at any chip, heatsink, power resistor etc and it tells you in less than a second how hot it is. Not super-accurate, but it's within a degree at most of the temps I measure. Great for checking temp rise in the motors and drivers I'm working on. :o) -Roman -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Yea, I've got a FLUKE 80T-IR that I use a t work. It is indeed a very handy and almost indispensible tool for what I do. I work in an advanced engineering lab and I use it all the time for measuring the temperature of many different things. Such as soldering temp, heat rise in IC's, room temp, resistor temp in prototype circuits, etc., etc. You get the idea. Very good investment. Regards, Jim On Wed, 03 January 2001, Roman Black wrote: {Quote hidden}> > Hi, anyone here got a non-contact infrared > (emissive) thermomter? I got one for xmas and > it's great. You can point it at any chip, > heatsink, power resistor etc and it tells you > in less than a second how hot it is. > > Not super-accurate, but it's within a degree > at most of the temps I measure. Great for > checking temp rise in the motors and drivers > I'm working on. > :o) > -Roman > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics spam_OUTjimTakeThisOuTjpes.com -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

> the temperature of many different things. Such as soldering temp, > heat rise in IC's, room temp, resistor temp in prototype circuits, > etc., etc. You get the idea. Very good investment. Another (way off-topic) use is in working on cars. In a former life I was a mechanic, and we used it to test for stuck / broken thermostats, clogged heater / oil hoses, etc. More than once it was used to measure how "hot" we were. Didn't work :) -Steve -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Roman Black wrote: >Hi, anyone here got a non-contact infrared >(emissive) thermomter? I got one for xmas and >it's great. Boy, somebody sure knows how to keep "you" happy. :) -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics

Yes. Wondering if many people use them, and maybe hoping for some tips re what it's good for. :o) -Roman Eisermann, Phil [Ridg/CO] wrote: > > We've got one of those in our test lab. We use it to measure heat rise on > threaded steel pipe (its difficult to get a thermocouple in there). Are you > asking out of curiosity? > > {Original Message removed}

Apparently it's good for Christmas gifts... ;-) I can see myself using it to check the temperature on a thermister to help calibrate it, rather than securing the thermister and another sensor to a block of metal and waiting for both their temperatures to stabilize... -Adam Roman Black wrote: {Quote hidden}> > Yes. Wondering if many people use them, and > maybe hoping for some tips re what it's good > for. :o) > -Roman > > Eisermann, Phil [Ridg/CO] wrote: > > > > We've got one of those in our test lab. We use it to measure heat rise on > > threaded steel pipe (its difficult to get a thermocouple in there). Are you > > asking out of curiosity? > > > > {Original Message removed}

I wonder how they correct for emmisivity(sp)? Has anyone tried doing an accuracy test for something like a Kanthal furnace? What's the max temp on this? I have a need to read a target that is inside a (glass)clear envelope ( also hot) will it read the envelope or the target? tia-rf {Original Message removed}

robertf wrote: > > I wonder how they correct for > emmisivity(sp)? Has anyone > tried doing an accuracy test > for something like a Kanthal > furnace? > What's the max temp on this? I > have a need to read a target > that is inside a (glass)clear > envelope ( also hot) will it > read the envelope or the > target? Mine is a cheaper unit, measures -20c to +260c. It compensates with an internal temp sensor against the emissivity of the thing you point it at. This seems to work well. It may take 3 seconds to compensate when first turned on but then readings are 0.4 sec. Checked it against my quality mercury lab thermometer, seemed within a degree at temps up to about 70c (heatsinks). Instructions say +/-3degrees or 3% whichever greater, but the accuracy I measured was many times greater than that. Maybe if used in full sun or something it might be a bit off. In the workshop it was within a digit, 3 digit display no dp. I'm very happy with it, pointing it around the fridge I found lots of carrots at 0c, and one at 8c. My woman was laughing at my confusion, it was the carrot she put back in the fridge 5 mins before. Pretty impressive toy (sorry tool!) -Roman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Because the glass envelope is opaqe to IR, you will only read the envelope temperature and NOT the target inside. For proof of this, just look at a near IR image of a house. The windows always show up as dark even though the inside air and objects are much hotter. Same thing for a human face with eyeglasses. Eyeballs don't register because the glass lenses block the IR from the eyes. robertf wrote: {Quote hidden}> > I wonder how they correct for > emmisivity(sp)? Has anyone > tried doing an accuracy test > for something like a Kanthal > furnace? > What's the max temp on this? I > have a need to read a target > that is inside a (glass)clear > envelope ( also hot) will it > read the envelope or the > target? > > tia-rf > > {Original Message removed}

It very much depends on what kind of glass you're trying to look through. http://www.noao.edu/kpno/filters/sgt.html Roman Black wrote: {Quote hidden}> > robertf wrote: > > > > I wonder how they correct for > > emmisivity(sp)? Has anyone > > tried doing an accuracy test > > for something like a Kanthal > > furnace? > > What's the max temp on this? I > > have a need to read a target > > that is inside a (glass)clear > > envelope ( also hot) will it > > read the envelope or the > > target? > > Sorry I forgot to anser your second question. > I believe it will read the target. I was > doing the same with the roast in our oven, > was able to measure the temp difference between > the meat and metalwork inside the oven through > the glass door. > > Think of it like a light meter, if you point > it at a bright light source inside a glass, > or inside a lesser "glow", it will measure the > most intense light. > -Roman > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Robert Rolf wrote: > > It very much depends on what kind of glass you're trying to look > through. You obviously know more about this than I do, but it occurs to me that you could do one set of tests with a thermocouple and compare to the reading on the non-contact unit. Surely this would give a simple chart or table that would then allow the more convenient system to be used with ok accuracy? -Roman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Because the attenuation of the glass varies with wavelength, and since the wavelength of the emission varies with temperature (white hot vs red hot) I don't see how one could distinguish a between the attenuation caused by the glass and the black body emission of the source. I suppose one could develop a look up table calibration for a particular setup, as long as the envelop temperature is known (since it would be contributing to the reading). Roman Black wrote: {Quote hidden}> > Robert Rolf wrote: > > > > It very much depends on what kind of glass you're trying to look > > through. > > You obviously know more about this than I do, > but it occurs to me that you could do one > set of tests with a thermocouple and compare > to the reading on the non-contact unit. > Surely this would give a simple chart or table > that would then allow the more convenient system > to be used with ok accuracy? > -Roman > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Robert Rolf wrote: > > Because the glass envelope is opaqe to IR, you will only > read the envelope temperature and NOT the target inside. > > For proof of this, just look at a near IR image of a house. The > windows always show up as dark even though the inside air and > objects are much hotter. Same thing for a human face with eyeglasses. > Eyeballs don't register because the glass lenses block the IR from the > eyes. Ooooh. Now there's a WHOLE HEAP of things I just have to test! ;o) -Roman -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

In message <007b01c075fe$9e87d960$c40d53d1@c525lab>, robertf <.....robertfKILLspam@spam@MICROBALANCE.COM> writes >I wonder how they correct for >emmisivity(sp)? Has anyone >tried doing an accuracy test >for something like a Kanthal >furnace? >What's the max temp on this? I >have a need to read a target >that is inside a (glass)clear >envelope ( also hot) will it >read the envelope or the >target? I saw a really nice one a few years ago, it used a Ricoh auto-focus lens (just like an SLR), it was used at a coal fired power station for maintenance purposes - they regularly recorded measurements at various places, looking for changes signifying a possible problem. This one would read a humans body temperature at 20-30 feet, and went up to seriously high temperatures - as they obviously need in a power station!. I suspect it was SERIOUS!! money!. -- Nigel. /--------------------------------------------------------------\ | Nigel Goodwin | Internet : nigelgKILLspamlpilsley.co.uk | | Lower Pilsley | Web Page : http://www.lpilsley.co.uk | | Chesterfield | Official site for Shin Ki and New Spirit | | England | Ju Jitsu | \--------------------------------------------------------------/ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

Robert, I worked on one of these with another guy on the PIC list (Gerhard Fiedler) several years ago. His unit was for the steel industry. It seems to me that it measured the temperature of what it was focused on (IR wavelength). Andy robertf <.....robertfKILLspam.....MICROBALANCE.COM> on 01/03/2001 10:30:00 PM Please respond to pic microcontroller discussion list <EraseMEPICLISTspam_OUTTakeThisOuTMITVMA.MIT.EDU> To: PICLISTspam_OUTMITVMA.MIT.EDU cc: (bcc: Andrew Kunz/TDI_NOTES) Subject: Re: [OT]: handy gadget I wonder how they correct for emmisivity(sp)? Has anyone tried doing an accuracy test for something like a Kanthal furnace? What's the max temp on this? I have a need to read a target that is inside a (glass)clear envelope ( also hot) will it read the envelope or the target? tia-rf {Original Message removed}

Robert, correction for emissivity is done by measuring several (three usually) bands. If the source is sufficiently diffuse it will not be fooled too much. Afaik, if you try to read a temperature through something then you need to correct for the something. In other words, measure temperature of transparent something, and measure inside the something transparent. Then you process the second reading to obtain the correct reading for inside. The formula involves the transmittance of the transparent something for the radiation of the inside something. Both temperatures must be read with the same kind of instrument and preferrably with a parallel beam (using refractive infrared optics). Peter -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.