Discrimination

[PAPPY]

Several of our members ( Especially some of the newer members to TH'ing) have been asking How does discrimination work?
A better word for discriminator is perhaps "Differentiator". At minimum or no discrimination, ALL Metal within the detectable range is detected.
As you slowly INCREASE the discrimination, pull tabs, small nails, foil and even mineralization are IGNORED (Rejected).
As you increase the discrimination, pull tabs, small nails, foil and even some GOOD targets (Such as gold rings and nickels) will be rejected.
The best way to learn the discrimination points ( The lowest discrimination setting at which an object is rejected) of your detector is to scatter some sample targets, such as coins, pull tabs, and foil on the ground from 1-2 feet apart.
Starting at "0" or your detectors lowest discrimination point, scan each taraget. Gradually increase discrimination and record the results. With practice, you should be able to determine whether or not to dig by listening closely to the target signals.
Hope this will help a little....PAPPY

[TaTonka]

Excellent advice. Thank You.

[Geo777]

Pappy thanks for the tip. I’ve learned the distinctive sound the Ace 250 makes when it hits a coin. I’ll try your tip tomorrow and might even put my gold ring in the grass and see what sound it projects.

[TonyinCT]

Every target that comes within the magnetic field created by the detectors search coil produces a current on the target. The amplitude of the "wave" that is created is "measured" by the detector. The discriminator circuit in a simple sense "phases" out certain "waves". What Pappy said is correct for basic disc controls however , many of todays detectors have NOTCH discrimination which you can set to notch out pull tabs and still find many rings and nickels . Detectors such as the XLT and DFX have 190 such notches that can be individualy set to find or not find a target.
Please remember , the more discimination you use on a conventional VLF detector , the less depth you get. There is always a trade off in adjustments made to any detector.Sometimes its to the good , sometimes its to the bad.
Hope this all helps but it is really just a breif explanation. There are more technical aspects to discrimination than told here.

[bill(de)]

Great points from Pappy and Tony, if i may add my 2 cents. I've found that 2 filter detectors such as the X Terra 50 , "wishing for a small coil" Minelab Advantage, Whites IDX , Fisher 1236x2 etc with slow sweep speed requirements and quick recovery reset speeds with small coils can be very effective picking out targets with disc settings higher than pulltabs in high trash areas. Larger coils used on most detectors will miss many good targets if discrimination is set too high in excessive trash areas and it only gets worse when soil mineralization is high.
I really believe that the most important point is to learn how to setup your detector for various hunting scenarios and perhaps the need to have a detector that will deal with higher discrimination situations.

I failed to mention the LUCK factor which is mainly how i find good stuff .