What The Heck Is Iar Anyway?

[martygene]

I believe that the D2 uses IAR on 2 programs, Relic and Goldfield. But I don't understand how it works in the field. I even saw a video on it and still doesn't make sense. If any of you feel like trying that'd be great but only if you feel like it. thanks  

[Gary XP]

Iron Amplitude Rejection, same as the ORX and Deus 1 Goldfield programs.

As I understand it, IAR rejects iron based on it's audio intensity and depth.

Big iron has a high intensity, small iron such as nails have a lower intensity. The adjustment is 1 to 5, 5 is the maximum rejection.

IAR is not the best way to reject iron as it has limitations, especially on some deep iron which can sound good.

Looking at it from a relic hunters point of view, deep iron is probably old iron.

Relic mode with IAR at 5 is still one of my favourite programs.

[abenson]

Iron Amplitude Rejection-settings 0-5 zero being off 5 being full on. It's for rejecting shallow or big iron targets. setting of 1 will breakup/reject the signal from near surface targets. The higher you set the IRA the deeper the iron rejection will work, to a point. Deep iron targets or targets in heavy mineralization may not be rejected using IRA. I never use it gold hunting. I have used goldfield (one the Deus 1) relic hunting and will usually run it all the way up in most sites.

[Chase Goldman]

The main problem with cranking up IAR is that it doesn’t play well with highly mineralized ground, which cause all signals whether ferrous or non-ferrous to sound broken up.  I usually run it at zero because I am usually relic hunting in hot ground and rely on target ID and the horseshoe display to tell me it’s iron under the coil.  Old habits are hard to break, so even in the mild dirt farm fields I am mostly hunting in now, I keep the IAR at zero and interrogate the iffy targets signals acquired in Relic mode by switching to one of the FMF disc “modes” like Deep HC or General while swinging over the target.  It’s really easy to switch between modes for target interrogation by using the +/- buttons to navigate back and forth between the user custom programs.

[martygene]

Chase... have you ( or anyone else) used D2 Relic in soil that isn't so mineralized? If you have to go to another program to check the iron, why don't you just use that program? What does Relic IAR do for you while relic hunting that the others can't do as well? I'm just having trouble trying to figure out it's benefits in the field vs. any of the other programs. Thanks 

[Chase Goldman]

41 minutes ago, martygene said:

Chase... have you ( or anyone else) used D2 Relic in soil that isn't so mineralized? If you have to go to another program to check the iron, why don't you just use that program? What does Relic IAR do for you while relic hunting that the others can't do as well? I'm just having trouble trying to figure out it's benefits in the field vs. any of the other programs. Thanks 

At this point I really haven’t had the opportunity to use the D2 in hot ground other than to test target signals in a test garden.  So my D2 outings have been in mild dirt.

To clarify, I don’t go to another program to “check iron”, I use the other program to better characterize iffy target signals as explained below.  

Relic is sometimes useful as a screening search mode because it gives a view of all targets in the ground because it is pseudo all metal with no disc.  In Relic (as with Gold Field), all targets in the ground sound off with VCO-like pitch audio (think gold mode on the Equinox).  This helps you quickly find dense concentrations of targets ferrous or non-ferrous.   But it has no tone ID so you have to constantly check visual TID whenever you get an audio hit which is fatiguing once you are in a target-rich area. Furthermore, it is not a super deep mode because it tops out at a higher frequency (24 kHz max frequency).  Sometimes I will do my field surveys in Deep HC (14 kHz max freq) with pitch audio and Iron Volume with Disc at about 6 or 7 if I want to search deep.  If I encounter an iffy mixed signal I may interrogate it with either program to see if I can get a better ID in the other mode to make a dig decision.

Once I am in a target rich area, I either switch to Deep HC (14khz) or General (40 kHz) in full tones (and zero or slightly negative disc and higher reactivity settings for separation) so I can use tone ID.  I will then switch between modes and circle the target on iffy target signals to see if I can get it to lock on an ID or at least lock in as ferrous or non-ferrous.  I call this target interrogation and switch modes because each of these FMF modes use different frequency profiles and signal processing algorithms which can help a target which is iffy/borderline in one mode, lock in or provide audio clues in another mode because of better depth or sensitivity to small or mid-conductive targets.  You are in effect flexing the different muscles (strengths) of the different modes on a target to get it to come into focus.

I would say I spend 75% of my time in Deep HC and 20% of my time in Relic and 5% in General or Mono.  I only go to Mono if EMI forces me there because target IDs are much more stable and accurate in the FMF modes.

HTH