Want to rent a Good Metal Detector to 40 Feet

As most of you realize, we no longer see "two box" units for sale these days. One box connects two coils separated by a longer than normal distance or even disconnected coils. In days of old when battery life was measured in minutes rather than hours, two boxes held more batteries and the time between full power and discharged was dismally short. Today, battery life is not really an issue as our own internal needs for our body will most likely determine how long we can work outdoors.

We will probably always refer to the large, two coil units as a "two box" solution as long as we old timers are still around.

Maximum depth for the best of them? Around 25 feet at the absolute outside. It has nothing to do with the design or the machine. It has to do with audio frequency absorption in the soil. GPR is far less so rule that out - limited to around 2 1/2 feet or so. There is no way to physically penetrate beyond that 25 foot barrier based on the laws of physics. Anyone who tells you they can do that is exaggerating.

There are other technologies out there such as acoustic sounding, magnetic anomaly detection and sonar (depends on ground structure and makeup). Some of these are unlimited in their depth sensing ability but you can't expect them to find what we typically search for. They can map the earth nearly down to the molten core but couldn't find even the largest chest of gold. Our sensors have no yet reached the ability of those on Star Trek. Beam me up, Scotty!

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Those machines are not what GD was talking about, The GPX5000 is a Pulse induction detector and the Nokta is a VLF I think you need to go to there sites and see what they are but only believe about 30% of their listed facts the only one with real proof is the Minelab,

good luck, AU

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		Quote:			Posted by acalicaran
	GD, the other technologies you are referring to such as acoustic sounding, magnetic anomaly detection and sonar, are these the technologies of Minelab GPX 5000, Nokta Golden King, Lorenz Deepmax x5 and the OKM Black Hawk? These are expensive machines and their sophistication might be not ideal for a new user like me?

None of them are easy to use when you need to go to 40ft. Acoustic sounding requires dynamite and bedrock at no deeper than 600ft. Magnetic anomaly detection detects deep metal objects but also detects mineral deposits. Sonar is very unwieldy and hard to use on land targets. The depth on that will vary but accuracy is limited by soil conditions. None of these will work is your bedrock is too close to the surface.

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http://www.thunting.com/smf/index.php/topic,46262.msg254812.html#msg254812

YAR but  my mum will only lone me 7 hands     l.o.l if you are real ??

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http://www.thunting.com/smf/index.php/topic,46262.msg261324.html#msg261324

For a depth of 40ft they need those Big yellow detecters that go by the name of Caterpillar  . cheers Mick

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