We tried to make as easy as possible. Simply power on the device, select the alloy you're looking to test from the built-in database, and then place your sample on the sensor. If your sample is consistent with the selected alloy, the display shows a result in the expected range.
Our patented technology tests a sample's characteristic resistivity. Basically, the sensor in the device generates a very small electromagnetic field and measures how your sample bends that field. We know how a genuine sample would bend the field, and the device compares your sample's test results to the known good result. If they are consistent, that's considered a pass.
The PMV Investor and PRO can test a samples density using their onboard sensors (or the External Bridge when using the PRO). There is a sensor above and below the sample which can measure the thickness, the user enters the weight, and the device knows the density of the selected alloy. That leaves only one variable left: the diameter of the coin (or length/width for a bar). The device then displays how big the sample should be, and as long as your sample matches the displayed size, then the sample's density is consistent with the selected alloy.
Yes! All of our devices can test through plastic cases, holders, flips, and assays. As long as there's no metal in the case, it should be able to test through the plastic. Some cases are trickier to test than others, but those are rare.