Message:

<p>[QUOTE=&quot;Gallienus, post: 2886329, member: 42034&quot;]I&#039;ve done weighing of coins but never s.g. Even for simple weighing I&#039;ve found it necessary to buy a Ohaus Analytical scale. The usual $99 digital jewelers&#039; scales are simply not accurate. They will show a small coin as being lighter and a heavy coin as weighing more than they should. Thus it&#039;s not just calibrating to a single value to get the correct weight, but the weighing behavior of common commercial scales is not linear.</p><p><br /></p><p>I have a certified ASTM weight set for calibration.&nbsp; These are not too expensive depending on the accuracy desired ($20 or $40 for .01 or .001 gm I recall).&nbsp; They get more $ for a higher accuracy</p><p><br /></p><p>Now if the weight is off even a little, the s.g. could be off by a huge %.&nbsp; The problem is that the densities of pure copper and silver are &quot;relatively&quot; close to each other.&nbsp; It&#039;d be better if they used an Iridium/ Aluminum alloy but such is life.&nbsp; Also I can&#039;t find evidence of the use of scientific method in your paper.&nbsp; Have you done any further checks?[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in