CTX 3030 Target Size - How to interpret?

[RaisingPossibilities]

I have owned a CTX 3030 for about 5 months now. It appears to be an awesome machine. I am trying to get a better understanding of target size. My question may be a bit confusing, so I will try to pose it using a very simplistic example. The question is: What kind of algorithm/formula does Minelab use on the CTX 3030 to determine the graphical representation of target size in the target cursor on the detect screen? For example, lets assume an ideal situation where a dime is laying fairly flat in the ground at a depth of 3 inches. In this example, the dime is detected and the detect display is showing the entire target cursor circle filled in. Next, now lets assume the same dime laying fairly flat in the ground is at a depth of 6 inches, is detected, and is showing up on the detect display. How much of the target cursor circle should be filled in for the 6 inch deep dime? The 6 inch dime is twice as deep as the 3 inch dime, so should only half of the target cursor circle be filled in? Putting it another way, what size object at what depth fills the target cursor circle and how is the amount of the target cursor circle filled reduced with increasing depth? Also, sometimes, for partially filled target cursors, one side or the other will be filled in. What does this indicate?

Thanks

 

[pacer]

Great question.

 

[Jason in Enid]

I don't think there is a correlation, at least I haven't seen one. The "red blob" of cursor is simply a visual image of the FE-CO numbers the machine is seeing. A near-coil, air test should give you the smallest dot because the number will vary the least. A deep, corroded, iffy target should be the largest but it's not going to be a real relation to depth, and it would change from target to target.

 

[sube]

quote Also, sometimes, for partially filled target cursors, one side or the other will be filled in. What does this indicate?


Very good observation I have seen this when I started using the ctx but I have dug coins with it filled on the left and right only half the cursor . My conclusion or opinion would be the coin is not laying flat tilted left or right just a opinion not based on fact . sube

 

[Champ Ferguson]

You want to be cognisant of the depth of the target too when making the call. eg a shallow piece of canslaw may have an indistinct 'halo' of red pixels, but a deep nickel could look very similar.

 

[sube]

A word about nickels , Nickels seem to have the biggest difference in target #s weather there on edge tilted or with iron or non-ferrous targets or deep .

#s can come In at 12.04 to 12.18 you may get a 12.04 and 12.18 and all #s in between on the same target , target trace will be smeared in the nickel area audio will be fuzzy sounding .

Most of the time when you can't make heads or tails of the audio it's smeared just like the trace but trace will show you where the smear is on the screen making it easier to guess at where it is really coming in at . If I get a flash of 12.13 anywhere in my sweeps I will be digging . It seems nickels can read all over maybe because they are a low conductor that can up average and down average a lot more then pennys dime's and other high conductors . This happens when the nickel is not flat on the ground or mixed with other signals .

One other point about nickels with iron you well get a trace below the 12 line non-ferrous with a nickel will have a trace but well be blended giving you a 12.17 if with a tab or higher depending on the size of the tab. Foil will lower this reading . What I look for is the nickel being in the nickel range when in iron it will display a curser with no red basically a flash of a black circle it will be at 25.13 then go to 17.13 if you see the curser traveling from the bottom of the screen trying to get to the 12 line (DIG) this go's with all coin targets penny dime and so on . It works better with nickels because generally with higher conductors it want to hit 12.40 or 12.48 when in iron this is where iron wants to false making it harder to tell if the coin signal is trying to get to the 12 line . Where as the nickel is on the other side of the screen the iron still may try to get to the 12 line and display a trace in the 12.40 to 12.48 area so you can assume this is a nickel with iron . Just watch that cursor in the nickel range if it's trying to get to the 12 line please dig .Also when using pinpoint sizing with trace it tends to build the target at 15.09 to 15.15 below the 12 line because of the iron .

This is probably why you don't see more post with people finding nickels with nails foil and tabs lot's of post with pennys and dimes .

As for more red in the cursor the bigger the coin the more red verses a smaller coin at the same depth also sensitivity if running higher well give a better trace in trace and pinpoint trace sube

 

[RaisingPossibilities]

Thanks for all the info!