TID/VDI range of accuracy

[all iron]

Monte mentioned this in a previous post and i wanted to start a quick thread to continue this topic.
Its so easy to rely on the Metal detector to tell us "For Sure" what is in the ground
I am so guilty of this. Most targets that i have recovered have been well between what i would consider the range of accuracy.

I / we need to consider the detectors ability to "detect" but not accurately depict what is in the ground beyond the range of accuracy.

The next time i go out, i will dig all targets that are "detected" with no regards to target accuracy "deep targets" that is, to help understand target TID/VDI responses.

Definitely part of the learning curve.

 

[Monte]

the numeric range and how tight (or not) the readings are, then make the recovery. I don't look at the TID, just the VDI. I mainly look for consistency, but I also don't rely on it when a desired target might be over 3" or so deep. That is, if using a typically 'average' or 'stock' coil of 8" or larger. When in brushy or trashy sites and using a good smaller coil (5" DD) then I ignore the TID as well. I know the VDI is similar, but not the same. I use the VDI for info only, not decision making, but I glance for consistent read-outs regardless of possible depth.

I look forward to hearing how you do in future reports. Too often we see people recover only the rock-solid, lock-on TID's, then they wonder why they don't find more good stuff. Just too many variables we have to deal with because deeper targets might not ID right, and masked targets don't, either.

Hope you hit some good stuff!

Monte

 

[earthmansurfer]

This last Monday I went detecting and kept an eye on the VDI. Of the 4 coins I dug, all were in iron, and the VDI for all was a bit jumpy or had a wide range. So, after covering the whole I would check to see if there was iron around - and yes there was. A couple of the coins were not great signals because of the iron, but were repeatable in 4 directions. When iron is around the hits on the coins aren't as sharp of course in mode 4, but in mode 2 they sound great.

I also checked targets with the rear of the coil as Monte describes in his pdf, that really helps to id iron caps (and even iron containing targets).

 

[Pops]

As stated in other posts the best discriminator sits between your ears, you can't rely solely on the detector to figure it out for you. Case in point, this week I had a jumpy signal in the 85 to 86 range. Probably just trash but because the area had given up some old silver in the past I wanted to know what the target was. It turned out to be a crumpled aluminum pie pan AND a silver rosie next to it. You have to use other information not available to the detector to make the final decision. On the other hand in almost every city park you can find thousands of pull tabs. I dont dig all the 57 to 62 signals I come across because experience and the location tell me they are probably pull tabs. But if they read in the 50's and not reach 59 I dig. My experience tells me this is the area of nickels and gold jewelry.

I've had the T2 since March 08, my normal starting settings are 3 tones, disc 21 and sensitivity as high as the area allows. I have dug thousands of trash targets and hope to dig thousands more. This is a long way of saying that your experience and the location you are hunting is the best determination as to dig or not.