Reply to Thread

Message:: [QUOTE="-jeffB, post: 2786919, member: 27832"]Be careful in the face of a sales pitch. The video showed the device reading SILVER through GOLD plating. That's a very different challenge; silver is highly conductive and not at all magnetic, and gold plating is far too thin to interfere with the resulting signal. The video also showed the device identifying .999 silver, but rejecting .999 silver plated over -- well, he doesn't say what the interior of the coin is. If it was steel or another magnetic material, I'm quite sure their $700 machine could distinguish it from silver. Of course, so could a 10-cent magnet. What the video did not show is the machine distinguishing between pure silver and silver-plated copper. The electrical differences between copper and silver are very small -- the conductivity difference is around 5%, and the permittivity/susceptibility difference is a couple hundredths of a percent. It's possible that Sigma is able to pick this difference up, but I'm not convinced, and the video does nothing to convince me. Like [USER=84179]@Oldhoopster[/USER] says, for this to be an actual underweight 90% silver planchet, you need a whole stack of unlikely coincidences. For it to be a silver-plated clad quarter, misread by a machine, all you need is a common plated coin, and physics.[/QUOTE]