Very nice. The proper name of the thermo electric effect is the Seebeck Effect named after the guy who discovered it. The yellow plugged thermocouple you were using is type K (chromel/alumel) which is good for about -30 deg C to + 1000 deg C and is pretty linear. The more common is the type J (iron / constantan) which is good for about -40 deg C to about + 600 deg C. You get a little better resolution from the type J but it is not as linear as the type K. Note that all thermocouple response is NON-LINEAR which is why the calibration is important. The standard in thermocouple pyrometery is Type S which is Platinum/Rhodium. The millivoltage produced is not very much compared to those using base metals but it is very good for higher temperatures like 1500 + deg C. You can look up all of the millivoltages produced by the various thermocouples in the International Practical Temperature Scale. That should be available on the internet if any of your viewers are interested. Good video.
Good demonstration! We use the type K thermocouple on the big diesel engines I work on. They are used for exhaust temperature sensors. The thermocouple connects to a special module that measures the millivolts and sends it to a PLC controller, reading in °F for the program to display. The PLC will monitor the temperature and give various warning alarms if any one cylinder gets too hot or too cool.
Love your shows - why didn't I have someone like you as a teacher when I was at school... interesting, enthusiastic, actually knowledgeable... Thanks again, keep them coming.
Take two thermocouples and connect them together, iron to iron, copper to copper etc. Put one thermocouple in ice and heat the other, read the voltage across them. Callibrated thermocouples require a cold junction (ice) reference. Either with ice which is not practical or electronically simulated in a thermocouple meter. Without the cold junction, the voltage will be unstable and not reliably indicate the temperature. Good stuff! Thanks for all the great information!
I am in the process of setting up a gas furnace for my shop. I was working on it and I thought that the thermocouple would make a good topic for your video. I know how it works, but it was fun to watch you play with. Thanks! Mike
The New Horizons probe that recently flew by Pluto was powered entirely by thermocouples with the heat generated by decaying plutonium. The system is called a Radioisotope Thermoelectric Generator (RTG).
Thanks again. You tested the home made wires and showed the current change. I was hoping you might have connected that to that one meter you had the jumper wires on to show the actual temperature change. Good video all the same. Harvey.
Quite interesting. I have a small gas heater that had been recovered from a razed travel trailer, it uses a thermopile/coupler to not only operate the safety shut off for the pilot light, but also provide power for the thermostat. The current one operates well enough to keep the pilot lit, but not enough to operate the thermostat circuit. Finding a replacement in that style (wire ends) is being a challenge. I miss that heater on really cold nights, it's good for sitting close to with a good book.
These videos are amazing... They're so incredibly informative, and really down to the point. if you are searching for Thermocouple manufacturing please visit our video th-cam.com/video/yoVnLRLmK_k/w-d-xo.html
If your voltmeter has a thermocouple setting it has a way to know the temperature of the internal terminals. The temperature delta of the junction is relative to temperature of the loop. Short out the terminals on the meter with a wire (made of one metal e,g, a paper clip or copper jumper) and see what the temperature is. Note the old meter wanted you to add an offset by adjusting it to room temperature.
BRILLIANT video... dissimilar metals simply react, and the reaction is done by the way of electrons, and electrons in action is electricity. in the old west, dissimilar metal plates sunk into the earth could create enough power to send a telegram! and heat, like a battery's electrolyte (fluid, acid...), is also a catalyst (or accelerator) of this process. PLEASE STOP APOLOGIZING FOR GIVING US YOUR RANDOM THOUGHTS -- they are filled with pure gold.
Thermocouples are really interesting (and useful). Thanks. My dad used to make thermocouples by welding the tips of the wires together. He used a car battery and a big knife switch. He would touch the wire tips together and rapidly close and open the knife switch. The tips would weld themselves together. It took good timing, careful alignment of the wire tips, and it only worked well about one time in ten. Still, what's time to a hobbyist with an interesting project? For those with a technical interest (it's tough going for a non-physicist) check these Wikipedia articles: en.wikipedia.org/wiki/Thermoelectric_effect en.wikipedia.org/wiki/Thermocouple For most of us the fact that it does work will suffice. One interesting fact about thermocouples is that they actually measure the *difference* between the temperatures of two or more dissimilar-metal junctions in a loop. In a pyrometer, or in a thermocouple attachment for a multimeter, the second junction is in the meter and is at room temperature. The meter has to do the math to convert the difference in temperatures to a readable, absolute temperature of the junction in the probe..
A regular Mr. Wizard. I imagine if you use an op-amp as a signal amplifier you can get better readings from your homemade thermocouples. Indeed the Internet is just chock full of example circuits. Very simple stuff too. Hmmm, could be useful for a project I've planned here.
if you buy an Analog Devices AD595 chip it amplifies a type K thermocouple to a handy 10mV per degree C instead of the approximately 44uV per C. put a 10nf ceramic capacitor across the input or it may also act as a short wave radio!
Mark Sinden That is all well and good, except for the buy the specialized part bit. Especially being as general purpose op-amps are almost literally a dime a dozen. I've bought 50 for $5 at any rate. So a dime a piece I suppose?
+Paul Frederick - the problem with just an op-amp is cold junction compensation. The specialist chip handles that for you. Of course, you may prefer to do the compensation yourself instead.
Mark Sinden Where I am thinking about using something like this I am not interested in the cold temperature at all. More like a range of about 350-500F, or perhaps a sweet spot in that range.
Tubalcain, let me know if this blows your mind ... I have heard someone describe the idea of an engineered product that would use the useless vibrational energy of matter, and channel it into controlled heat energy, in other words, power from the random motion of matter at the atomic level. Being funny and serious at the same time, I'd love to see you turn this out on a Bridgeport.
Nice video - didn't know you were into "electronics" as well. All multimeters nowdays (even cheapest chinese) can go to mV scale. There is much more into thermocouples then just this tho - you don't need 2 different wires to read a voltage rise/drop when heated.. the voltage is relative to difference in temperatures on ends of wire (if you heated both ends, you would read 0v).. watch?v=AYblSfpKRUk
Very nice. The proper name of the thermo electric effect is the Seebeck Effect named after the guy who discovered it. The yellow plugged thermocouple you were using is type K (chromel/alumel) which is good for about -30 deg C to + 1000 deg C and is pretty linear. The more common is the type J (iron / constantan) which is good for about -40 deg C to about + 600 deg C. You get a little better resolution from the type J but it is not as linear as the type K. Note that all thermocouple response is NON-LINEAR which is why the calibration is important. The standard in thermocouple pyrometery is Type S which is Platinum/Rhodium. The millivoltage produced is not very much compared to those using base metals but it is very good for higher temperatures like 1500 + deg C. You can look up all of the millivoltages produced by the various thermocouples in the International Practical Temperature Scale. That should be available on the internet if any of your viewers are interested. Good video.
+Steve McEntyre Thanks for watching
Good demonstration! We use the type K thermocouple on the big diesel engines I work on. They are used for exhaust temperature sensors. The thermocouple connects to a special module that measures the millivolts and sends it to a PLC controller, reading in °F for the program to display. The PLC will monitor the temperature and give various warning alarms if any one cylinder gets too hot or too cool.
+davida1hiwaaynet Thanks for watching
Love your shows - why didn't I have someone like you as a teacher when I was at school... interesting, enthusiastic, actually knowledgeable... Thanks again, keep them coming.
+FVP Thank you very much--would like to have had you.
Thank you for the video, I enjoyed the project and overall the very good explanation. It brought me school memories.
Thank you Mr. Pete. I love watching this "how it works". I never got to see this as a kid, but now that I am a big kid it's fun....
+Kenneth Bartlett Thanks for watching
Take two thermocouples and connect them together, iron to iron, copper to copper etc.
Put one thermocouple in ice and heat the other, read the voltage across them.
Callibrated thermocouples require a cold junction (ice) reference. Either with ice which is not practical or electronically simulated in a thermocouple meter. Without the cold junction, the voltage will be unstable and not reliably indicate the temperature.
Good stuff! Thanks for all the great information!
+carambatsr I read about all that, but its too much info for that simple video
I am in the process of setting up a gas furnace for my shop. I was working on it and I thought that the thermocouple would make a good topic for your video. I know how it works, but it was fun to watch you play with.
Thanks!
Mike
+Junk Mikes World Thanks for watching
I always did wonder how they worked. You really are a good teacher!
+Englehard Dinglefester Thanks for watching
The copper and steel one you made created enough voltage to hold a typical pilot light on...nice video, thanks.
+dale pratt Thanks for watching
The New Horizons probe that recently flew by Pluto was powered entirely by thermocouples with the heat generated by decaying plutonium. The system is called a Radioisotope Thermoelectric Generator (RTG).
+Eric Morrison Did not know that--Thanks for watching
Thanks again. You tested the home made wires and showed the current change. I was hoping you might have connected that to that one meter you had the jumper wires on to show the actual temperature change. Good video all the same. Harvey.
thanks for sharing sir interesting as always..
+Kevin Willis Thanks for watching
Quite interesting. I have a small gas heater that had been recovered from a razed travel trailer, it uses a thermopile/coupler to not only operate the safety shut off for the pilot light, but also provide power for the thermostat. The current one operates well enough to keep the pilot lit, but not enough to operate the thermostat circuit. Finding a replacement in that style (wire ends) is being a challenge. I miss that heater on really cold nights, it's good for sitting close to with a good book.
That was fantastic, thank you!
+Metal Tips and Tricks (Dale Derry) Thanks for watching
These videos are amazing... They're so incredibly informative, and really down to the point. if you are searching for Thermocouple manufacturing please visit our video th-cam.com/video/yoVnLRLmK_k/w-d-xo.html
If your voltmeter has a thermocouple setting it has a way to know the temperature of the internal terminals. The temperature delta of the junction is relative to temperature of the loop. Short out the terminals on the meter with a wire (made of one metal e,g, a paper clip or copper jumper) and see what the temperature is. Note the old meter wanted you to add an offset by adjusting it to room temperature.
+Richard J Lebens Thanks for watching!
Very interesting, good info. Thanks as always Mr. Pete!
+ShysterLawyer Thanks for watching
Good video. I had one on the Mack I use to drive. It was attached to the housing of the turbo.
+Mike C. thanks for watching
Very interesting! Thanks for teaching us something, Tubalcain!
+W.Co.VIDS Thanks for watching!
Thanks Mr.Pete! You are THE MAN!
+Mr Frog Thanks for watching
This will be a good one for me and the little guy.
+MrHevyshevy Yes, do it--Thanks for watching
Well, that was very cool! I believe it calls for an explanation of bi-metal thermostats!
+Fernand Geene Van Thanks for watching!
Always interesing, ever informative. Thank you.
+John Strange Thanks for watching
BRILLIANT video... dissimilar metals simply react, and the reaction is done by the way of electrons, and electrons in action is electricity.
in the old west, dissimilar metal plates sunk into the earth could create enough power to send a telegram!
and heat, like a battery's electrolyte (fluid, acid...), is also a catalyst (or accelerator) of this process.
PLEASE STOP APOLOGIZING FOR GIVING US YOUR RANDOM THOUGHTS -- they are filled with pure gold.
+KevCarrico Thats good info-thanks for watching
Thermocouples are really interesting (and useful). Thanks.
My dad used to make thermocouples by welding the tips of the wires together. He used a car battery and a big knife switch. He would touch the wire tips together and rapidly close and open the knife switch. The tips would weld themselves together. It took good timing, careful alignment of the wire tips, and it only worked well about one time in ten. Still, what's time to a hobbyist with an interesting project?
For those with a technical interest (it's tough going for a non-physicist) check these Wikipedia articles:
en.wikipedia.org/wiki/Thermoelectric_effect
en.wikipedia.org/wiki/Thermocouple
For most of us the fact that it does work will suffice.
One interesting fact about thermocouples is that they actually measure the *difference* between the temperatures of two or more dissimilar-metal junctions in a loop. In a pyrometer, or in a thermocouple attachment for a multimeter, the second junction is in the meter and is at room temperature. The meter has to do the math to convert the difference in temperatures to a readable, absolute temperature of the junction in the probe..
Peter W. Meek thanks very interesting!
Jimmy Diresta said to come check you out! Looking forward to learning something. Thanks!
+Brad McDonald welcome-thanks for watching
Very interested , once again u amaze me & again I learned something new.
+Dave Graham Thanks for watching!
Great video! Thanks for sharing.
+My Heap Thanks for watching!
Really informative video, thanks sir!
A regular Mr. Wizard. I imagine if you use an op-amp as a signal amplifier you can get better readings from your homemade thermocouples. Indeed the Internet is just chock full of example circuits. Very simple stuff too. Hmmm, could be useful for a project I've planned here.
+Paul Frederick Thanks for watching
if you buy an Analog Devices AD595 chip it amplifies a type K thermocouple to a handy 10mV per degree C instead of the approximately 44uV per C. put a 10nf ceramic capacitor across the input or it may also act as a short wave radio!
Mark Sinden
That is all well and good, except for the buy the specialized part bit. Especially being as general purpose op-amps are almost literally a dime a dozen. I've bought 50 for $5 at any rate. So a dime a piece I suppose?
+Paul Frederick - the problem with just an op-amp is cold junction compensation. The specialist chip handles that for you. Of course, you may prefer to do the compensation yourself instead.
Mark Sinden
Where I am thinking about using something like this I am not interested in the cold temperature at all. More like a range of about 350-500F, or perhaps a sweet spot in that range.
Great video, always wanted to know how one works!
+Gary Papesh Thanks for watching!
I like these videos, very cool, thanks!
Tubalcain, let me know if this blows your mind ... I have heard someone describe the idea of an engineered product that would use the useless vibrational energy of matter, and channel it into controlled heat energy, in other words, power from the random motion of matter at the atomic level. Being funny and serious at the same time, I'd love to see you turn this out on a Bridgeport.
No problems holding aluminium and/or nails in my mouth, since I don't have amalgam fillings. Nowadays they use composite fillings.
+PuchMaxi1988 You are lucky-it hurts
+mrpete222 Our neighbour once said to me: How can you hold nails like that, even looking at it hurts my mouth!
awesome info .thnks
I have an old Alnor Pyrometer (0-1600F) with no thermocouple. How do I find which type is used for my meter?
Sorry, I'm afraid I cannot help you with that
Would you be able to do a load cell video similar to this one? I like your style a lot
+jackfrost1031 Whats a load cell?
+mrpete222 a load cell is a weighing device. The measured voltage changes when a load deflects the cell.
en.m.wikipedia.org/wiki/Load_cell
I believe that a galvanometer uses an iron vane meter movement - it's been years since college.
+Barry Naviaux I don't remember that either. Thanks for watching
interesting video as always!
+Jeff Moss thanks for watching
thanks father, i learned a lot
You are quite welcome, my son
very cool. lesson learned . thanks
+krazziee2000 Thanks for watching
very informative! thanks
+Michael Murray Thanks for watching
Nice video - didn't know you were into "electronics" as well. All multimeters nowdays (even cheapest chinese) can go to mV scale. There is much more into thermocouples then just this tho - you don't need 2 different wires to read a voltage rise/drop when heated.. the voltage is relative to difference in temperatures on ends of wire (if you heated both ends, you would read 0v).. watch?v=AYblSfpKRUk
Interesting
+Robert Perrigo Thanks for watching
Thermocouple deez nuts