Salt Sensitive Setting Test Results

[ColonelDan]

As promised in a separate post, I conducted a test to determine the lowest salt sensitivity setting possible that allowed for stable operation and greatest depth detection.  What prompted this test was the conflict in the hard copy user manual compared to the on line version.  The hard copy stated that the higher the salt sensitivity setting, the more that targets with a TID of around 30 would be attenuated.  The online version stated that the lower setting would attenuate those same targets registering a TID of around 30.  I questioned the hard copy version saying that if the higher salt setting was true, then why not just use a salt setting of 1 and be done with it. To clarify this whole thing I tested two separate targets on a wet salt sand beach where the waves would come in and completely cover the test area.  I chose that area to ensure that the salt mineralization would create some level of chattered response.

The two targets used for the test were a small and very thin 10k ring whose TID registered as a 45.  The second target was a thin gold chain with a TID of 33.

I buried them both at a constant depth of 4 inches.  I didn't want to go any deeper so as to avoid depth limitations impacting the results as a separate variable throughout the test.

With a sensitivity setting of 95, I did the normal frequency scan with the reactivity set at 1.    Ground balance was a constant 86.  I then started with a salt sensitivity setting of 9, scanned both targets separately and then  incrementally lowered that setting until I reached a salt sensitivity of 1.  As expected, the higher the setting, the more chatter was present but the detectable signal was stronger.  As I lowered the setting the more stable the Deus II operated but the signal strength was reduced incrementally until it was gone.    I continued to raise and lower the setting until I found what I considered the "sweet spot"---that setting where the chatter was minimized but the target signal was a definite "digable" one.  On New Smyrna Beach that day, under those test conditions, the "sweet spot"  was a salt setting of 5 for the gold chain and 2 for the gold ring.  To caveat these findings, keep in mind that my results at New Smyrna Beach that day would most likely be different than the same test run at Virginia Beach for example.  Every beach is somewhat different so my "sweet spot" settings are not the universal gospel for every salt water environment according to Colonel Dan.  Your results on your beach may very well differ....and probably will. 

Bottom Line: adjust your salt sensitivity to best suit the conditions you face that day on your beach.

[cdv]

Good info Dan, thanks for taking the time to do this and report back.  No doubt each beach will be somewhat different however knowing this allows for the fear of mis-adjusting the detector to be of less concern and gives some reassurance to how you set up the machine. I'm sure someone can find a target on some beach that can prove your testing wrong.... time will tell.

In Square Pitch tones in the water in a slightly modified Beach program I am using a setting of 7 for Salt balance and I do have some chatter from irregularities of bottom and minerals. Volume of that chatter is low and I use it similar to a threshold tone so I know my machine is on..... getting over any target normally screams at me with an Audio Response of 5 and Sensitivity on 93. Other settings are BC 3, Disc 7, Iron Vol. 3, Reactivity 1, Silencer 0.....  BUT, that is my beach and my preferred settings.

Cliff

[midalake]

3 hours ago, ColonelDan said:

I continued to raise and lower the setting until I found what I considered the "sweet spot"---that setting where the chatter was minimized but the target signal was a definite "digable" one.  On New Smyrna Beach that day, under those test conditions, the "sweet spot"  was a salt setting of 5 for the gold chain and 2 for the gold ring. 

HI Dan
Great info! 
Did you try to keep the machine in S.S.9 and clean up the noise by lowering sensitivity? 

The reason I ask, when testing on deep gold we found the machine had the ability for the same depth at 88 sensitivity. It was below this point with sensitivity 87 and lower that the D2 seem to lose depth. 
I was out with my Equinox yesterday and will be today, but hope to get that D2 out by the end of the week and will test lowering the sensitivity with keeping salt sens at 9.
We had a hurricane out in the ocean and it is very rough here. 

 

[ColonelDan]

1 minute ago, midalake said:

HI Dan
Great info! 
Did you try to keep the machine in S.S.9 and clean up the noise by lowering sensitivity? 

The reason I ask, when testing on deep gold we found the machine had the ability for the same depth at 88 sensitivity. It was below this point that the D2 seem to lose depth. 
I was out with my Equinox yesterday and will be today, but hope to get that D2 out by the end of the week and will test lowering the sensitivity with keeping salt sens at 9.
We had a hurricane out in the ocean and it is very rough here. 

 

I did not adjust the sensitivity setting below 95.  My test objective was to limit the number of variables in this particular case to just the salt sensitivity.  However, a test that maintains the salt sensitivity constant at a given level and adjusts only the sensitivity setting would certainly be worthwhile.