Tuesday, March 28, 2017

Good target numbers

Although I often use a metal detector with an array of discrimination features, I am still the main discriminator. 
If I'm searching for older stuff at the beach I rarely use much discrimination and I rely heavily on my target depth read outs.
A little discrimination may help you to identify and reject unwanted shallow targets, but if you are not careful, it may also make you miss desirable deeper targets you are searching for. 
People new to metal detectors with screens and target probability numbers, tend to obsess over target numbers too much. 
I get umpteen emails a week from people with target number questions. My response is usually to forget about target numbers and instead check out the number of inches on the target depth read out.
Assuming you use a little discrimination, an iffy signal response from a shallow reading target is almost always going to be your metal detector doing a good job of identifying a bad target. 
An iffy signal response with a deep target reading is worth digging up, or at least scrape a few inches of sand away from the area and double check. 
When a metal detector with discrimination has difficulty identifying a deep target, it will almost always reject deep targets as probably undesirable junk.
The threshold of a metal detector using discrimination, will null / blank over a deep target or give a broken iffy target response,  
That is why the only number I always look at first on a metal detector screen when using a little discrimination is the target depth number.
I rely on my metal detector discrimination to reject the easy to identify shallow targets, then I rely on the help of the target depth readout.
On my last trip to Oak Island Nova Scotia I recovered many musket balls that gave iffy signal responses, using the CTX 3030 with the large 17 inch search coil.
A quick glance at a maxed out target depth readout and moving a little top material with the side of my boot,  prevented me from walking away from deep targets. 


The target depth gauge is  one of the best features of a metal detector with a display screen, when you understand that metal detector target IDs are only accurate to a certain depth.




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