How does the PMV work?
The Verifier works by analyzing the resistivity of the metal sample. Resistivity of various metals is very different and even small variations in alloying results in different resistivity. Conductivity value for base metals are well known and can be found on Wikipedia and other web sites.
How do I use PMV?
PMV usage is very simple. Power unit on, wait for calibration to finish, select metal you would like to test and place the sample on sensor or place external wand over the sample. Resistivity reading takes just seconds. Each unit comes with a User Guide and there are several videos available with instructions.
How do I know which sensor to use?
The small wands are for reading very thin and small samples, for example 1/10 oz coins, 1 gram bars, and CombiBars. Some slabs have high walls which make it difficult for the main sensor to reach far enough to get a reading. The large wand can sit on the flat part of the slab and often measure coins that the main sensor cannot. The large wand is also useful for rapidly reading coins in albums or cases without removing the coins. Accurate measurement requires that the sample must completely cover the sensor. The higher the resistivity of the metal, the deeper the signal penetrates.
How and when is the unit calibrated?
The unit is calibrated whenever the metal is changed, when the unit is turned on, if the sensor is changed, or on command by the user. Usually recalibration is unnecessary. However, if odd readings are obtained (typically coins that are thought to be good at reading out of range), one thing the user should do is recalibrate to make sure the instrument is giving correct readings.
Does it need maintenance or consumables?
No. PMV does calibration internally, and has nothing that is consumed. All you need is to charge the battery.
Can the wrong metal give an answer that looks right?
It is almost impossible to duplicate another coin's resistivity, weight, and size. For example, silver is the most conductive metal known, so it is virtually impossible to duplicate. Gold is the third most conductive metal (only copper is between them). Platinum and Palladium have almost identical conductivities but are easy to distinguish in other ways.
In principle it would be possible for an alloy to be developed that would mimic, for example, American Eagle gold. But combined with the appearance and weight of the coin, the fake would be obvious. A coin that has about the right weight (for example using tungsten to fake gold) would have a totally different resistivity than gold.
Can the right metal give an answer that looks wrong?
The results of the Verifier measurement are affected by the coin temperature, the coin stamping relief, and by the coin alloy. Temperature is compensated for in the instrument and is a fairly small effect, so except under very unusual circumstances will not be a factor. Only when the sample has been left in a hot car or out in the cold will it typically come into play. Generally, a hot coin (hotter than the instrument) will read to the right a little bit, and a cold sample will read a bit to the left.
Coin stamping relief is easy to see on the coin. The PMV already assumes a typical stamping relief and the effect is typically small. However, some medallions and molded coins have extreme relief and will read a little bit to the right. This is not typically seen in conventional coins because the relief is too small. On bars, areas that have heavy embossing or bubbles and flaws will sometimes read slightly to the right. Usually reading the opposite side or in another location will remedy this effect.
Can the PMV be used with jewelry?
The PMV does not work well with jewelry for two reasons. First, we need to know the specific alloy we are measuring and then determine if the item being tested falls into the range of that alloy. Jewelry alloys vary considerably. Each different combination would have its own range. The number of variations is too great to be included in the default database. The second problem is that we need a flat area of metal that can be completely covered by the sensor. Jewelry is often curved, woven, and/or ornate in a fashion that makes it so we cannot get an accurate reading on it. Also, necklaces, rings, and earrings are usually too small for even our small sensor to get an accurate reading. We have some success looking at sterling silver flatware and it often matches up with the sterling silver range on the PMV, but there are also pieces that we just cannot measure.
How do I recharge the battery?
The battery is a standard lithium-ion battery. You can use the charger and cable that come with the unit. You can also charge the unit from another mobile phone charger, the USB connector from a computer, the USB connector in your car, or the USB connection on an power outlet.
Is the PMV safe to use?
Yes, the PMV uses very low power, low energy signals and doesn't emit any dangerous radiation.
What is the difference between the two bars on the display?
The top bar measures just the surface of the bar a fraction of a mm deep. Even so, this is deep enough to look under hundreds of plating thicknesses. The bottom bar is the thru measurement that goes completely through the sample and can detect any deeply buried counterfeit metals.
How can the PMV PRO measure the density of the bar?
The user selects the metal type and enters the weight of the sample. As we can measure the thickness of the sample, we can then show an image on the display to match what the diameter, or rectangular shape should be. If the sample does not match this defined shape displayed on the screen, then it must be an incorrect density.
What does the number next to the displayed image mean?
The number on the display is the characteristic resistance (resistivity) in micro-ohm per cm. This number can be found on Wikipedia for base metals and other web sites. Using the setup screen on the unit we can change the display to show the number is a different manner, characteristic conductance (conductivity), in micro-Siemens per cm.
Can I buy sensors for the PMV PRO, which I already own?
Yes, but for correct functionality it is necessary to send your unit back to the factory for calibration.