Written by the Treasureguide for the exclusive use of the Treasure Beaches report.
I decided to do a little experiment to compare Minelab Equinox conductivity numbers with Manticore numbers. I used the Beach 1 setting on the Equinox and the General Beach setting on the Manticore. Sensitivity on both was 20. The test targets were a copper memorial penny, clad nickel, clad dime, clad quarter, junk ring, silver ring, and gold ring. The first chart below shows the results for the Equinox and the chart below that shows the results for the Manticore.
The charts look very similar, but there is a big difference in the numbers. There is a big difference in the range of numbers. The vertical axis on the Equinox chart goes up to thirty while the Manticore vertical axis goes to 90.
The lowest numbers were produced for the same objects on the Equinox and Manticore. In fact, the relative position of each object was the same for both detectors. The conductivity numbers produced by both detectors going from lowest to highest were first, the junk ring, then the gold ring, followed by the nickel, penny, dime, silver ring and then the quarter, which produced the highest number on both detectors.
The differences between the numbers produced by each object increased as the numbers got higher. For example, the difference between the Equinox and Manticore numbers was for the junk ring was only 3 points.
For the high conductivity objects, such as the quarter for example, the difference was 58 points. The Equinox reading for the quarter was 29, while the Manticore reading was 87. So, for the higher conductivity items the difference between the Equinox and Manticore readings became larger, but for all objects the Manticore conductivity number was the higher or the two.
The main thing to know is that if you transition from an Equinox to a Manticore, the conductivity numbers will be different. The nickel number on one will be different than the nickel reading on the other.
The conductivity numbers for both detectors seem to be similarly consistent although there will inevitably be some error variance. The numbers will differ as a result of a variety of factors. I've talked about that before.
Manticore numbers will generally be higher, and the difference between detectors increases as you get into the higher conductivity items. At this point, I don't know if the higher end of the Manticore scale permits greater discrimination between high conductivity objects. I don't know if the variance in the numbers for those higher conductivity numbers also increases.
The graphic Target ID map of the Manticore seems to provide additional useful information. Of course, both detectors provide tone differences that are also useful.
I didn't compare depth of detection in this experiment but might do that in the future.
Here are the approximate conductivity numbers for the Equinox for the seven test targets in order of conductivity. The Manticore numbers are on the next line.
Equi. 3. 8. 13. 21, 25. 27 and 29. (junk ring, gold ring, nickel, penny, dime, silver ring and quarter.
Mant. 6. 13, 27, 60, 77, 85 and 87. Objects are in the same order.
So the differences are 3. 5, 14, 39, 25, 58 and 58. Again, same order. Increasing differences with increasing conductivity numbers.
The danger, which you might have noticed, is the similarity between the junk ring and the gold ring. The gold ring number in this case is a low number, which unfortunately falls in the range of other junk targets.
I've discussed several times before the wide range of numbers than various gold items can produce. We only used seven test targets in this short test, but gold items of various types produce a very wide range of numbers. So do junk items. And occasionally other items will produce the same numbers as a clad quarter, for example. T
I suspect that across various detectors that show conductivity numbers, similar results will be seen as related to the Equinox or Manticore. Different detectors will produce different numbers of different items, but relative position of various objects will be the same. I haven't verified that, so let me know if you know that is wrong.
You won't always get the same number when you seep over an object. A number of an item like a quarter might be an 87 and and 88 or something else. It might center around 88, for example, but you'll occasionally see on your screen some other numbers. Among the factors that affect the number is the coil position relative to the item as well as other things. The variance also increases at near borderline depths, for example. But if you continue to center the coil, you might get a pretty repeatable specific number. There numbers popping up on your screen might be imagined as distributed something like the bell curve shown below. There is a best number, or center number but also some variance.
The test I conducted to compare the Equinox and Manticore on conductivity numbers is just a sloppy little test with many serious limitations, but it seemed worthwhile. I might follow up with some other tests in the near future. There are many interesting things to look.
===
 |
| Sebastian South Beach from the Beach Cam. |
It looks like they are building a wall to the south of the pier. Is that what is going on?
 |
| Surf Chart from SurfGuru.com. |
It looks like a few days of really small surf. Good time to get down at some low tides.
Also with the freeze and drought we had this year, it might be a good time to hit some of the overgrown areas.
Good hunting,
Treausreguide@comcast.net