Sunday, October 12, 2014

10/12/14 Report - New Storm Likely To Develop Soon. Video Demonstration of Effect of Metal Detector Coil Sweep Angle and Object Position.

Written by the TreasureGuide for the exclusive use of

Gold Ring Used in Today's Demonstration.

There is some big weather news, but first I have something else for you.

Today I have a very good video demonstration for you that clearly shows some things that I've talked about in the past but also illustrates additional important information.   The video shows how the sweep angle and position of various objects can affect a metal detector signal.  Using that new information will help you better understand how your detector works and what type of object you are detecting.

For this demonstration I used the Ace 250 because it is well suited for this purpose.  I used All Metals mode.

Other detectors will give similar but different results.

I used three test objects: a screw, a thin rectangular copper tag, and a thin gold ring.

First I put them all flat on the ground.   I swept my coil over the first two in one direction and then at roughly ninety degrees.

I did not bother to change sweep directions on the ring when it was laying flat because it is nearly round and the sweep direction would not make any difference.

The video shows the different signals you get when you sweep over an oblong object such as a screw in one direction and then again at a 90 degree angle.

The next part of the experiment involved standing the rectangular copper tag and the gold ring upright.

When the tag was put on end, it gave a signal like iron instead of the coin-like signal it gave when laying flat.

The ring when standing on end, gave a broken signal when sweeping in one direction and a solid signal when sweeping the other.  That was very much like the signals given by the screw laying flat.   When the ring was standing up, it presented an oblong surface to the coil and gave a signal like what you would expect from an oblong object.

You can tell quite a bit about objects from the signals.

Here is the link to the demonstration video.   Pay close attention to the signal and tone over each object.  Notice how the signal changes when the sweep angle changes on some objects and how the signal changes when some objects are stood up.

The most important things that I'm showing today is that the sweep angle will affect the signal, as does the position of the object in the ground.

If the copper tag was pushed into the ground at a forty five degree angle instead of straight up and down, it would give an even more variable signal.  And if it is bent, the signal is even more variable.

The most simple case is a round object, such as a coin, laying flat.

In the past I've talked about how you can identify oblong objects such as nails with detectors such as the Minelab Excalibur.  Sweeping in one direction you'll get a broken signal, while sweeping at ninety degrees will give you a solid signal.  You could see a similar thing with the screw in this video and also with the ring standing up using the Ace 250.

Although the Excal and Ace are different in many respects, they both identify long thin nail-like objects with a broken tone in one direction and a solid tone in the other direction.

I can always identify a nail or similar object with the Excalibur in all metals mode.   The Ace reacts similarly.

You should now better understand why the signals of some objects are so variable and some of the factors that can cause that.

The signal can tell you a lot if you really understand your detector.

On the weather front, Fay is heading out into the Atlantic and away from the Treasure Coast, but what I've been calling Disturbance 1, now has a 90% chance of becoming a cyclone, and it looks like it will be moving towards us.

As I've been telling you, we often get some good hunting in October or November.

That is something to watch.

Happy hunting,