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<p>[QUOTE=&quot;Conder101, post: 3654271, member: 66&quot;]What is the precision of the scale?&nbsp; How many test runs did you do?&nbsp; Where results consistent among other control specimens as compared to the subject coins? (Did you test other 1981 canadian cents and 1982 US cents to make sure you weren&#039;t running tests on an &quot;odd&quot; piece?)&nbsp; If you are trying for precise SG figure (more than one decimal place) are you isolating from drafts and compensating for temperature of the water?&nbsp; Where did you get composition specs for the Canadian cent?&nbsp; I know they are bronze but not the actual official composition percentage specs.&nbsp; Do you know that making up a melt it is very difficult to impossible to hit a planned bronze or brass composition to within a couple of percent since the tin or zinc in the alloy boils at a lower temperature than the copper melts.&nbsp; It isn&#039;t just a simple matter of adding the proper amount of each metal and melting them.&nbsp; Take too long to create the melt, or hold it molten too long and the whole time your zinc is boiling off.&nbsp; The actual composition of the melt is a moving target.&nbsp; If you can hit the target within 2% you&#039;re good.</p><p><br /></p><p><br /></p><p>This is curious because with the Canadian coin being bronze and US coin being brass, and the copper percentage probably being in theory about the same I assume, the densities should be as well.&nbsp; You are getting a measured value for the US cent between 8.91 and 9.02.&nbsp; The spec SG is 8.83.&nbsp; The measure values are higher than the spec value but the high value is still about just 2% high, the lower just 1%.</p><p><br /></p><p>An XRF test would be illuminating.&nbsp; If the Canadian coin is actually bronze as it is supposed to be I would expect to see a reading for tin, possibly a significant reading.&nbsp; Tin was eliminated for the US cents in 1963 so any more than a hint of tin would be reason to question.[/QUOTE]</p><p><br /></p>

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