# Testing an S type thermocouple



## jimdoc (Dec 30, 2010)

I recently purchased this item;
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=230559955557&si=NGBN%252BLkojd2JPvc3y%252F07g2OQX98%253D&viewitem=&sspagename=STRK%3AMEWNX%3AIT

Upon receiving it when I opened it he had it in a 4-5" coil taped to styrofoam.
When I cut the tape it sprang out like it wanted to be straight,I thought that and the color didn't seem right.I then noticed a dark spot of oxidation on the middle of both wires like someone had flame tested it already.I then checked the Salt Lake Metals platinum wire calculator,and according to that it should have weighed about 2.95 grams.It weighed 2.1 grams,and in his auction he stated it weighed 1.7 grams.
With all of those bad signs,I then put each tip into the flame of a propane torch.Both tips started to melt in seconds,so I stopped.It may have beaded up the ends about 1/16 of an inch or so.And both wires seemed the same,and both started to bead up in a second or two.
So I packed it back up and returned it.He gave me a hard time about returning it without trying to work something out.And I told him as far as I was concerned there is nothing to work out since I did not think it was platinum,nor did I want it.
As far as I know platinum should not have beaded up like that within a second or two in a propane flame.I have a few other samples of platinum wire that I have had glowing and does not melt,and cools with no signs of oxidation.I wouldn't test very thin wire like that,but this thickness I did not expect any melting.Also every pure platinum wire I have seen is soft and fairly easily bendable.This was not.
So did I make a mistake here,I know I could have used an acid test or even a touchstone test could have been a better choice.He tried giving me a partial refund of $20 telling ebay I destroyed it and he can no longer sell it on Ebay.I declined it and told him I wanted a full refund,and will have to appeal Ebay's decision.If it is platinum he should have no problem selling it.


What would be the best way to test a used thermocouple?

Thanks. Jim


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## lazersteve (Dec 30, 2010)

You could have clipped off a tiny (1-2 mm) portion from the end of the wire and dissolved it with hot AR to check for PGMs.

Steve


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## jimdoc (Dec 30, 2010)

Steve,
Thanks.That was my first thought,but I was trying not to alter the length of the wire in any way.I did not expect it to melt within a few seconds.

Jim


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## jimdoc (Dec 31, 2010)

Does anybody think that a S-type platinum thermocouple should melt in a propane torch flame in seconds?

Jim


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## nickvc (Jan 1, 2011)

Jim I was going to reply yesterday but time seemed to run out.
Your test is something that I would have done, heated to red heat to see if it discoloured and i would have also tested it it with acid to eliminate stainless steel. If your torch is just a simple propane torch your not going to be able to melt platinum if it's in reasonable proportions as it doesn't get anywhere near hot enough to melt it, if I remember correctly platinum needs nearly 2000 degrees to melt and propane burns at around 1500, add forced oxygen then yep it'll melt platinum.


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## jimdoc (Jan 1, 2011)

nickvc said:


> Jim I was going to reply yesterday but time seemed to run out.
> Your test is something that I would have done, heated to red heat to see if it discoloured and i would have also tested it it with acid to eliminate stainless steel. If your torch is just a simple propane torch your not going to be able to melt platinum if it's in reasonable proportions as it doesn't get anywhere near hot enough to melt it, if I remember correctly platinum needs nearly 2000 degrees to melt and propane burns at around 1500, add forced oxygen then yep it'll melt platinum.



Thanks,now I know I am not going crazy.

Here is his first reply to me;
Jim Regretfully, you in incorrect. The melting point of platinum is 3214.9 F. http://en.wikipedia.org/wiki/Platinum The heat that a propane torch can deliver is 3623 F. http://en.wikipedia.org/wiki/Propane_torch Check out these links to prove my statement correct. Because of the small size of the wire, it would be very easy for anyone to melt Platinum. I have never received any of them back since all of the text in my auction is accurate. You should engaged in a discussion on this before sending it back to me. Here is a NASA scientific paper link that states oxidation can occur on platium at elevated temperatures. (400 C. = 752 F.)http://adsabs.harvard.edu/abs/2003AIPC..684..345A

Also, I maintained mesh belt brazing furnaces that ran at 2,020 F. that used this type of thermcouple. They always had a haze on them when they were removed. Since I never had one analyzed with an electron beam microscope, I can not agree with the statement that the haze was actually oxidation. I worked as a metallurgist in an electrical contact manufacturing company for a decade. I have no idea what basis you are using to make the statements in your email. 
- tep43in1

Now if a simple propane torch could get to 3623F,I should be able to melt my palladium wire,that I can not.Wikipedia doesn't mention the fact that oxygen,and possibly a furnace is needed to get that hot.

I posted this to see what others thought and also to warn you about this seller.As far as I am concerned he robbed me of $58.91,and then offered me $20 of that money back as partial refund,with the stipulation that I don't leave him negative feedback.He claimed that the item was destroyed and he could no longer sell it on ebay.Now if it was platinum/rhodium like he states in his auction,how is 2.1 grams of that not able to be sold?The very tips of the wire were only slightly melted,He might have a point if I melted the whole thing,or a large portion.
This is the most dishonest seller I have run into in many years.

And Ebay isn't much help at all their buyer protection is as much as a joke as trying to get a hold of them.I am seriously thinking of canceling my account.If they aren't going to protect you like they say,then paypal is worthless.I have another case open with them for a counterfeit kingston flash drive from China,that I highly doubt I will ever see my money back.

Remember think twice about dealing with tep43in1 on Ebay,you have been warned.

Jim


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## Claudie (Jan 1, 2011)

To me, this seems no different than someone offering to sell a solid brass coin and stating that it is made of solid gold. If the item was advertised as Platinum & it wasn't Platinum, then he misrepresented it and you should get a full refund. I think I would also try to contact Paypal to cancel the transaction, I'm not sure how they work in a case like this but some credit card companies will take care of things like this for you. It might be worth a try.


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## jimdoc (Jan 1, 2011)

Claudie said:


> To me, this seems no different than someone offering to sell a solid brass coin and stating that it is made of solid gold. If the item was advertised as Platinum & it wasn't Platinum, then he misrepresented it and you should get a full refund. I think I would also try to contact Paypal to cancel the transaction, I'm not sure how they work in a case like this but some credit card companies will take care of things like this for you. It might be worth a try.



To ebay it seems that his claim that I damaged it by putting flame to it is more important than anything else.The fact that the flame helped prove it wasn't what was advertised doesn't seem to phase them.They don't have a clue.I thought a thermocouple is supposed to be able stand up to some heat,silly me.I already wasted an hour and a half on the phone,what a waste of time.And I am sure I will be having to call again when I appeal the case.I can't see him being able to call it destroyed and not able to be sold if it is platinum.He is a total thief as far as I am concerned,and Ebay is helping him.

Jim


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## Lou (Jan 1, 2011)

If he sold it as scrap, then he can hardly call it destroyed. It wasn't a new item I'm sure, otherwise he would've gotten more for it.

Having seen, worked with, made, digested, and handled about every type of thermocouple wire over my years in the laboratory, my first question is this:

1. What gauge was the wire? In the very best circumstances you *can* get fine filament platinum to melt in a propane flame (fyi, the adiabatic flame temperature he quotes is theoretical, not actual as it does not include radiative losses and assumes a perfectly tuned flame under ideal circumstances, it's really about 3000-3100F in practice). By fine filament, I mean thinner than a hair. I've never seen thermocouple wire than thin and I'm sure it doesn't exist. 
2. You said it was springy--this can happen, but it isn't common. Usually 'tis soft gray and easily moved about. 
3. Did you look at the bead you made or the weld junction? They should not be oxidized. 


Pt wire doesn't oxidize and stay oxidized at room temperature--this means that you can heat it up and at some point it might form a superficial oxide, but it will not remain. The same is true for the PtRh alloys.

Lou


EDIT: Confirming what I said and showing his vain attempt to rationalize his mistake (and perhaps fraud, seeing as he is a metallurgist and should know better):

"PRTs were soaked at different temperatures, and the resulting changes caused by oxidation and the subsequent dissociation of the formed oxide were observed. Soaking below 400 °C initiated oxidation, in some platinum resistance thermometers (PRTs), and then their resistance steadily increased with increasing temperatures up to about 525 °C. When soaking near 525 °C, the resistance of the PRT remained stable, suggesting that the thermal energy ``kT'' equals the energy that binds oxygen to platinum, at the existing oxygen pressure. At temperatures higher than 525 °C the formed oxide dissociated. The higher the temperature, the higher the thermal energy and thus the higher the rate of dissociation. One hour of soaking near the Al point dissociated the oxide that took hundreds of hours to accumulate. Three out of seven PRTs tested however would not oxidize while soaking for several months. Further soaking, however, did initiate oxidation in two of the three PRTs. "

That's from the NASA paper (really wasn't NASA by the way).

To quote my old professor "In this world, you meet alkynes"


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## jimdoc (Jan 1, 2011)

Lou,
There was oxidation in the middle of each wire(not the junction)like someone had already tested it there,I didn't like that.He claimed it was .020"/.51mm in diameter in the auction,that is the figure I used in the Salt Lake calculator.It wasn't anywhere near as thin as a hair,it was a solid wire.

I have at least 5 or more other samples of pt. wire and none of those oxidized,or melted either.Some of those are thinner than this wire.

Both legs of the thermocouple seemed like the same type of wire,it almost looked like it was bent at the joint and with a little bead there.I didn't like the look or feel of it,and the melting in a propane flame in a second or two really made me sure it wasn't platinum.That is why I didn't waste my time testing with acid.

I had never dealt with a used thermocouple,so I was unsure about the stiffness of the wire.Every picture I see of scrap platinum wire looks like the stuff on Midwest Refineries website.I also bought this auction;
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rt=nc&nma=true&item=200558456737&si=NGBN%252BLkojd2JPvc3y%252F07g2OQX98%253D&viewitem=&sspagename=STRK%3AMEWNX%3AIT
I am confident that this is platinum because I have bought from him before.I don't know what it is from,I was thinking maybe corona wire because of his Ebay ID.

Thanks. Jim


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## lazersteve (Jan 1, 2011)

Is it possible the bead on the tip is the only portion of the thermocouple that is Pt and the leads up to the bead where the wires meet is a different metal?

Steve


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## jimdoc (Jan 1, 2011)

Steve,
It all looked to be the same metal,it actually almost looked like it was just bent in the metal with a bead there.It was not the wire in his picture,he must have lifted that from somewhere else,or maybe it was one he previously sold.
If I was smart I should have taken pictures before I sent it back.I didn't expect to have any problems,but who ever expects problems?

Jim


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## Claudie (Jan 1, 2011)

Looking at his feedback, I see another buyer purchased what appears to be an identical auction.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230553703227
This buyer seemed to be pleased as they left a positive feedback for the seller. Maybe you could try contacting this buyer, and discuss the situation with him/her. 
The seller also states "There are no surface or metallurgical defects on this item" you might try again to explain to Ebay how this item was misrepresented.


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## jimdoc (Jan 1, 2011)

Claudie said:


> Looking at his feedback, I see another buyer purchased what appears to be an identical auction.
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230553703227
> This buyer seemed to be pleased as they left a positive feedback for the seller. Maybe you could try contacting this buyer, and discuss the situation with him/her.
> The seller also states "There are no surface or metallurgical defects on this item" you might try again to explain to Ebay how this item was misrepresented.



Yes,actually two other people bought a similar item from him,he used that as an excuse also,that they didn't have any problems.He may have actually sent them the right item,or maybe they trusted him and didn't check it.

Jim

I just contacted both of them,lets see if they respond.

Thanks. Jim


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## Lou (Jan 1, 2011)

There should be no oxidation on the wire at all. 

Steve, it is very unlikely that it would be so. While one would think this is cheaper to do, it is almost never the case that an S/R/W or any noble piece goes to a non-noble "transmitter" on its way to the potentiometer. I'm not saying that it doesn't happen, but that I've not seen it personally.


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## jimdoc (Jan 1, 2011)

Well,
Both of the other buyers got back to me and neither one tested their thermocouple.I gave both links to this post so they can share the info.
I hope they can do something with Ebay if theirs tests negative also.
I have the sellers phone number if they need it.

That blows the sellers "none of the other buyers had any problems"
excuse.I wonder how many people buy stuff like this and just trust the seller.

Thanks. Jim


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## jimdoc (Jan 5, 2011)

I am done with Ebay.They are ruling in favor of the seller because they did not authorize the return of the item,and that the item was damaged.They told me that I could appeal,but that would not change the outcome.
They don't care about what I have to say at all.

I am deleting my Ebay account and will never deal on there again.
Remember tep43in1is a very dishonest seller.
How I wish I lived close enough to see him in person.

Thanks for all your help.
Jim


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## turtlesteve (Jan 5, 2011)

For the record, if you paid with credit card (or if you paid with paypal and used a credit card as a funding source), you can issue a chargeback on your card if you're scammed - doesn't matter who Ebay sides with, you can get your money back.

Also, if you're a seller, watch out as this can be used as a scam as well - buyers can claim foul, issue a chargeback, and end up with your item AND the money. For this reason I will never sell anything with significant value on Ebay.

Steve


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## jimdoc (Jan 5, 2011)

Here are my last ebay messages with this thief;
Dear jimdocjr,
Jim, I have been informed by eBay that they did not rule in your favor regarding your complaint. They ruled in my favor. Since you failed to follow eBay's method of resolving a dispute, that is, by contacting the seller and attempt to work it out in a professional way, I choose not to try to work it out in that fashion now. You had your chance to settle this dispute like this earlier, but you failed to do so. Regrettfully this matter is now closed. Not only are you technically defficient, you are socially defficient. Both of these reasons are exactly why you are in the position you are in now. One of the buyers that you mentioned consider you a lunatic. Their word, not mine. Kindly,
Tom

Dear tep43in1,
You are nothing but a thief using Ebay's policies in your favor.Keep selling that wire and see if you don't get called out on it again.It is not platinum.
Jim

Jim, I request that you do not contact me or any of my sellers as a matter of record. I will be contacting eBay security and notify them of your activity with my sellers. That violate eBay rules and guidelines. I caution you that you will risk your privledge of trading on ebay if you do not cease and desist your activity. This will be my last communication with you. Do not respond to this message, for your own sake. Tom
- tep43in1

Hiding behind ebay's policies and using them to rip me off.
His feedback dropped from 100% to 85% because of his lack of dealing fairly.Maybe I shouldn't have sent it back without contacting him or ebay first,but using that as an excuse to not refund me,and his claiming the item was destroyed are both the signs of a thief to me.

I am giving up with ebay so I don't care what he does.And one of the buyers that I warned to check their purchase called me a lunatic?
I hope they enjoy their fake thermocouple.

Jim


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## jimdoc (Jan 10, 2011)

I just got an email from ebay;
MC014 FB Alert: Feedback abuse - eBay Information Alert 

Your eBay account has recently been involved in activity that violates our Feedback abuse policy. 
The following Feedback was left from your account: 
Not Pt. This seller refused refund when sent back claiming damage.What BS
This recent account activity doesn't follow our guidelines.

Looks like he complained to ebay and they removed my negative feedback.
No option to change it,its just gone.Helping him to rip off others in the future.I am sure he will be selling the wire I sent back to him, that he claims was destroyed.

Another reason for me to never do any business through ebay or paypal.

Jim


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## Claudie (Jan 11, 2011)

It is bad enough getting a bad deal, then having ebay take their side makes it even worse, but not even allowing the buyer to warn others is just wrong. No wonder there are so many scammers on there. I still think you should look into the credit card refund.


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## dtectr (Jan 11, 2011)

jimdoc said:


> I just got an email from ebay;
> MC014 FB Alert: Feedback abuse - eBay Information Alert
> 
> Your eBay account has recently been involved in activity that violates our Feedback abuse policy.
> ...


you can check out my opinion of FeeBay in this post. Amazingly, though, some folks here love 'em! :shock: 
http://goldrefiningforum.com/phpBB3/viewtopic.php?f=44&t=5588&p=81976#p81976


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## lubysan (Jan 12, 2011)

Hi,

I don't know where you live, but in my area ,(NYC), there's a small lab on 47th street that will test any metal with an XRF machine for $10. I've tested platinum thermocouple (99.982% result) and sterling silver that I thought was counterfeit (93.2%).
I'm told that many junkyards carry the portable version in order to sort their scrap by metal content and percentages. As long as the device is calibrated properly, it is supposed to be accurate to within +/- .5%. Hope that helps.


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## goldsilverpro (Jan 12, 2011)

Does anyone have a quick method for separating the Pt TC wires from the Pt/Rh ones?


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## Lou (Jan 12, 2011)

Hot concentrated sulfuric left on a coil of the Rh containing alloy will go slightly yellow-brown over several hours.

Failing that, I'd just check resistance if they're the same gauge.


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## g_axelsson (Feb 21, 2014)

goldsilverpro said:


> Does anyone have a quick method for separating the Pt TC wires from the Pt/Rh ones?


Twist the ends of the wires together (unless they are already welded), heat it up and measure the voltage across the ends. The positive wire is Pt/Rh 90%/10% and the negative wire is Pt.

Göran


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## pgms4me (Feb 21, 2014)

Gentlemen, I have seen this type of thing happen on ebay for the 15 years I have been selling on there. if you think its a problem now,you should have experienced it 10 years ago before buyer or seller protection. before paypal everything was done by mail for the most part. It really isnt as bad as it seems. their protection schemes are better than most big box store chains. I have had my share of poor deals. Ebay usually favors the buyer no matter what. My way out of this as a seller is to always refund the payment after the item is returned,even if the buyer damaged it.
I hope you gave the reason for opening your case is "item not as described" Even though he may claim it is platinum, they would normally still favor you as the buyer,if you had said it did not test as platinum. However you blew it by Using BS in your feedback, that was the policy violation. I have tried to maintain the highest possible seller rating,but I lost it because a buyer claimed I knowingly shipped a damaged item. what happened was their was a little tiny plastic piece that had tape over it. I put it there to protect it and he must have broken the piece while removing the tape,claiming that i taped it because it was broken. Even though I promptly refunded payment and followed all rules it still counted against me. the good news is that things like that seem to be 1 bad per 500 good. i either have to accept that or find another venue. I have spent too many years buliding up a good feedback rating to stop. Buyers beware. I also use type s thermocouple wire. It does come in different thicknesses, but you cannot melt either of the 2 wires in a propane flame. they will glow bright orange and that is it. Neither will type k or j melt under propane. I used a standard pencil flame torch to test


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