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 Replies: 71 / Views: 12,305 |
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Bedrock of the Community
United States
17884 Posts |
Quote:The standard tolerance test to silver planchets applied by The Royal Mint during the 19th century was that they should be within 2.5% of the standard weight (the weight specified in legislation). That seems to be very high. The US Mint Tolerance for the 19th century expressed as a percentage was only .3% or close to a tenth of what you are quoting. |
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Bedrock of the Community
United States
12477 Posts |
Taking the copper Lincoln Cent as an example, it should be 3.11g. I have the understanding that Mint tolerance was within 0.13g. By my calculations, the variance can be within 4.8% of the dictated weight. 0.3% is a fairly unrealistic standard. If you meant 0.3g then, okay. 0.3% of a copper cent's weight is 0.00933g. I'm pretty sure there's something amiss in the definitions here.  In Memory of Crazyb0 12-26-1951 to 7-27-2020
In Memory of Tootallious 3-31-1964 to 4-15-2020
In Memory of T-BOP 10-12-1949 to 1-19-2024
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Pillar of the Community
 United States
1901 Posts |
Ok guys so I did the test... Zinc penny on my scale weighed 2.4 in the water .4 I got 6 Copper penny on my scale weighed 3.1 in water was .3 I got 10.33 The 83 penny on my scale 2.1 in water .2 I got 10.5 That is the closest I can get but that means anywhere from 1.5 to 2.4... Where should I go from here? Find someone to do a xrf? Or what? Suggestions please  |
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Pillar of the Community
Canada
891 Posts |
Try contacting SPP Ottawa on the Canadian part of this forum, He has helped a lot of members
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Pillar of the Community
United States
1901 Posts |
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Pillar of the Community
United States
1901 Posts |
No body has any suggestions? Is the xrf the next step... or am I sending it to a third party with all the info I have obtained with it and see if they yield the same results?
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Pillar of the Community
United Kingdom
2135 Posts |
Mrzllewellyn,
I don't think weighing it with a paperclip will give a valid result.
From what I remember of Physics, you need to suspend it from something that has negligible mass, like a thin cotton thread.
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Pillar of the Community
United States
1901 Posts |
Pertinax go to page 2 and click link from cwb and read I did it exactly how it said but my scale only does 1/10 of a gram so that's why I ended up with 10 something but I did a known copper also so I can see what results I would get with that...
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Pillar of the Community
United States
3478 Posts |
What are your plans then Mrzllewellyn?
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Pillar of the Community
United States
1901 Posts |
I don't know I need guidance lol
Edited by Mrzllewellyn
09/17/2017 7:11 pm
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Pillar of the Community
United States
1901 Posts |
I'm thinking the lab at work has a better scale that does 1/100th or 1/1000th of a gram so if it does I will get a better reading if not I will stick with my findings my scale gave me till then any suggestions are greatly appreciated
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Pillar of the Community
United States
3329 Posts |
Since you have access to a lab, maybe measure the coin thickness with calipers for the thin planchet idea? Compare to several normal coins. May not be definitive, but who knows
"Nummi rari mira sunt, si sumptus ferre potes." - Christophorus filius Scotiae
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Bedrock of the Community
United States
17884 Posts |
Quote:
I don't think weighing it with a paperclip will give a valid result. You can do it with paper clip but you also need to do a run with the paper clip and without the coin so you and deduct the effect the paper clip introduces. I also don't understand why you are holding the paper clip. From the image I'm not sure you understand how to do a SG test. Quote:Taking the copper Lincoln Cent as an example, it should be 3.11g. I have the understanding that Mint tolerance was within 0.13g. By my calculations, the variance can be within 4.8% of the dictated weight. 0.3% is a fairly unrealistic standard. If you meant 0.3g then, okay. 0.3% of a copper cent's weight is 0.00933g. I'm pretty sure there's something amiss in the definitions here. Earlier you were discussing tolerance on SILVER coins not copper. The tolerances on silver were MUCH stricter. For example say you had a 1904 Indian Head cent, the .13 gram tolerance is like you said 4.18%. But if you had a 1904 Morgan dollar, the 26.73 gram coin had a tolerance of only .097 grams. That is .36% Gold coins were tighter. If you had a 1904 gold eagle it was supposed to weigh 16.718 grams with a tolerance of .032 grams or .19% Hence my statement that a Weight Tolerance for 19th century UK silver coins of 2.5% was way too high. Copper coins I might believe but not silver. Edited by Conder101
09/17/2017 9:35 pm
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Pillar of the Community
United States
1901 Posts |
Conder here is the answer to your question this is what someone put in the thread this is what I did  I took and put the paper clip in the water and hit tare it zeroed it out and I put the penny on the paper clip I took the number and decided the weight by it and got my answer so since I've explained what I've done this is what I got. Oh yeah and I just have access to a yarn lab they got scales and nothing else I can use but yeah Copper penny weighed 3.1 on the scale in the water .35 giving me 8.86 Zinc weighed 2.48 on the scale in water was .37 I got 6.70 The 83 I got 2.10 on scale in water .25 giving me 8.4 So I don't know what to do   Edited by Mrzllewellyn
09/17/2017 11:05 pm
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Moderator
 Canada
10463 Posts |
Quote:
The ONLY way to determine actual metallic composition would be XRF reading all the way into the coin Depending on the power of the beam source, the XRF can penetrate the coin's surface, but not very deep. Certainly deep enough to determined if it was a plated planchet or not however... "Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Replies: 71 / Views: 12,305 |
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Posted 09/17/2017 05:16 am
