❗Minelab alert: PLB - Accidental Activation

[Teemore]

Not sure whether this has been circulated previously, found on a recent FB post.

Subject: - Direct from Minelab
Hello Fellow Members. Doug
There have been some reports of customers having EPIRBs and PLBs activating when they have come into close contact with a metal detector coil when the detector is switched on.
We would like to reach out to you all so that you are aware of this so that you can also educate our customers with this information to help prevent any unnecessary activation of EPIRBs or PLBs.
Our engineering team have loaned detectors to Kinetic Technology International and they have researched the affects of the KTI PLB and our detector, the PLB was activated when it came within 10cm of the detector coil. Although this distance is very close we would like to make sure than any customers using EPIRBs or PLBs are aware of this so that they can keep their location beacons well away from the detector coil to prevent any false activations. Please keep this in mind particularly when a target has been removed from the hole and you are finding it with a scoop (you are physically much closer to the coil when this takes place.)
KTI have suggested to use a metal tin to carry your EPRIB or PLB in to help prevent this from happening. A metal tin will work as a faraday cage (faraday cages will break the electromagnetic fields that your detector produces.)
We agree that this is a good suggestion as it can assist in greatly reducing the risk of a false activation.
If you have any questions regarding this please feel free to contact me.
Kind Regards,
Jason Hosking
Technical Sales Representative
Minelab Electronics

 

[grubstake]

It was previously notified here, but there's no harm in repeating it IMHO:
https://www.prospectingaustralia.com/forum/viewtopic.php?pid=578834#p578834

 

[David-Karratha]

Interesting. I wonder if storing the epirb in a faraday bag would be as effective (and perhaps a little lighter) than using a metal container?

The only info I can find on the effectiveness of faraday bags, is a test by ECU where they tested their effectiveness at blocking 3G and 4g phone signals. Im guessing that the inverse square law however, would mean that the detector coil signal would be squillions of times stronger than that.

Another option that I was wondering about was to simply wrap the epirb with foil. I tried looking around the intertubes to see if this was plausible, however virtually all I could find was stuff from conspiracy theorists, who were either trying to hide from men in black suits, or constructing hats to keep the aliens from implanting ideas (or apparently any kind of common sense or logic) into their brains.

Are there any technical folk here whod be able to provide any guidance on this? I carry enough weight in my backpack as it is, not sure I want to add a tin can as well.

 

[Cranky Emu]

Are there any technical folk here whod be able to provide any guidance on this? I carry enough weight in my backpack as it is, not sure I want to add a tin can as well.

Wrapping or enclosing an EPIRB/PLB in foil, tin or whatever defeats the purpose of carrying one in the first place. A totally foolish notion - one that could possibly cost you your life.

The reason you carry an EPIRB is so you can summon help (RCC) in an emergency (life-threatening) situation. The easier it is for you to access and activate the beacon, the greater your chances of survival. Not having to dick around unwrapping or unpacking it first - which in some instances may be impossible for you to do.

If you have the EPIRB mounted on your harness near your shoulder for example, the chances of a detector setting it off would be very remote.

 

[condor22]

Equipment "added" to military aircraft that contains electronics not tested for EMI/EMC by the aircraft manufacturer, are to be contained in a metal box with no air gaps.
This prevents the escape of possible interference from spurious sources (Not air tight, but minimal holes or gaps in construction) and prevents the "smoking hole in the ground" result.

A tin box or alfoil will reduce or eliminate such interference, in both directions. Even metal gauze (small hole type) will act as a Faraday cage.

This also applies to civil aircraft. The bulk of such equipment added are passenger mobiles, tablets and laptops, which is why you are asked to turn them off.

 

[David-Karratha]

C.Emu - I dont disagree.

Some time ago I used a Spot gps/epirb device, which I carried on a pack strap, because it had the ability to provide regular movement & position updates, to allow 3rd party monitoring for those working alone in remote & hazardous areas. My current epirbs unfortunately, usually have to live in the top pouch on my ruck or camelbak (along with my other personal-carry safety & survival stuff). My shoulder straps are already typically carrying my gps and radio (or radio mic).

If all it takes is for me (or someone else) to casually swing a detector coil past my pack (either when Im wearing or when stopping for a quick break), it could potentially waste a lot of time, effort and resources.

The epirb manufacturers themselves suggest carrying the device inside a tin (see the original message above), which pretty much prevents it from being mounted on a shoulder strap or belt, and so the idea of a soft sided faraday cage with a Velcro closure, seemed like a reasonably neat way of storing and carrying one.

Condor22 - I was thinking of pretty much the same thing. I did actually wonder if a cheap faraday pouch (or even some dreaded foil), might stop the epirb signal, rather than trying to block the way stronger field from the coil? In the event of an accidental activation, I guess theres a danger of finding your epirb battery dead if or when you ever need it, however providing your pre-start checks include using the test button, I gues youd control for this risk. Pity there wasnt a personal epirb model available with user replaceable batteries, then Id have the option of carrying them outside of the device.

No matter, I just thought it was worth putting the question out there.

 

[condor22]

FYI, Google Faraday pouch There are heaps out there for mobiles, wallets card etc. Just a matter of finding one that suits.

https://aussecurityproducts.com.au/...ness-non-window-faraday-bag-for-mobile-phones

Is the first one I found and there are plenty more. Yes there are much cheaper ones off the internet, but I still believe you get what you pay for, lol.