All Metal versus Zero Discrimination

This is something that does not get discussed often that can really trip somebody up when getting a new detector.

Modern IB (VLF) detectors can operate in two basic modes. A true go beep on everything all metal mode or a discrimination mode. Discrimination modes use various filtering methods to help separate desired targets from the trash. The filtering takes away from overall depth and the target id gets flakier with depth. In nearly all cases a detector operating in a pure all metal mode will find targets deeper than a unit running in a discrimination mode.

It is possible to take a detector running in discrimination mode and set it to accept all targets. You are now running with zero discrimination, so the detector now beeps on all targets. The problem is that some detector manufacturers are labeling this as an "all metal" mode since all metals are being detected.

Unfortunately, you have not really turned off the discrimination. A true all metal mode employs no discrimination at all, it just directly reports a target. In zero discrimination the target is still being filtered, but you are telling the machine to report all filtered targets as good targets. The bad news is you still are losing depth compared to the true all metal modes.

Most metal detectors are made for coin detecting, and so most only run in a discrimination mode. You can set them to accept all targets, to run zero discrimination, but these units simply do not have a true all metal mode.

All metal detectors designed with serious prospecting in mind have a true all metal mode. The reason is simple. True all metal hits hard to find targets, either very deep items or very small, better than detectors running in a discrimination mode, even when set to zero discrimination.

This is so important to me that I will rarely ever consider purchasing a detector that does not have a true all metal mode. Be careful when buying a new detector that if you want a true all metal mode you do not end up with a detector that really is offering a zero discrimination mode.

It is possible for a detector to run in all metal and discriminate modes at the same time. This is referred to as mixed mode, but it is a subject all it's own so I have posted separately on it at http://www.akmining.com/forums/showt...=3876#post3876