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Will Magnets Harm GPS Unit?


JeLo34275

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I have a small leather cell-phone case that I'm thinking about using for my Venture HC. The top of the case has a flap that secures with a little magnet which I find easier to open and close than a zipper or velcro.

 

Will the magnet harm the data stored in memory and/or affect the accuracy of the GPS unit itself?

 

Thanks.

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I have a small leather cell-phone case that I'm thinking about using for my Venture HC. The top of the case has a flap that secures with a little magnet which I find easier to open and close than a zipper or velcro.

 

Will the magnet harm the data stored in memory and/or affect the accuracy of the GPS unit itself?

 

Thanks.

It should have no effect.

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I have a small leather cell-phone case that I'm thinking about using for my Venture HC. The top of the case has a flap that secures with a little magnet which I find easier to open and close than a zipper or velcro.

 

Will the magnet harm the data stored in memory and/or affect the accuracy of the GPS unit itself?

 

Thanks.

On the Garmin Oregon 400t approaching the unit with a magnet will affect its 2-axis electronic compass reading. It shouldn't affect data at all but it is generally not a good idea since if the GPSr has any ferrous material in it, and there must be something, it may pick up some perment magnetism from any magnetic source. Whether this would permanently damage anything or just cause more frequent calibration or no harm at all I don't know. If the Venture HC doesn't have an electronic compass then you probably have no concern. :rolleyes:

Edited by Ratsneve
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There is no compass in the Venture HC. Thanks to all who replied.

For other GPSr's that have 2 or 3 axis electronic compasses will passing weak or strong magnetic fields hurt the compass in any way? Will it affect the compass calibration requiring recalibration? Is there any permanent damage?? How about over a prolonged period even near a magnetic source?

 

Could a magnetic field set off other problems like jumping off course or position hundreds of feet?

 

I've used the Colorado and Oregon compasses while driving or riding in several vehicles without any problem since while moving the GPS compass has taken over. I just tried using the electronic compass inside my car while stationary, maybe for the first time, and it is quite impossible and unreliable for certain.

 

I hope/trust this may prove there is no harm done to the mechanism since the compass card movement is quite wild. There are it appears numerous points in a car, such as speakers, that greatly affect the Oregon's 2-axis compass pointing and operation. Even though I was holding the compass level I frequently got the "hold level" warning. This would of course be true using any sensitive magnetic compass too. I was surprised how sensitive the Oregon was inside the car--not needed but totally unusable while stationary imo.

Edited by Ratsneve
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Doesn't the Colorado have a small magnet in the rock-n-roller wheel?

I'm not certain now (another ten-year-old memory-fade) that the Hall Effect technology used has to use a permanent magnet but maybe just a ferrous material? Apparently, because I do remember reading a R-n-R thread not to long ago, you can use a small magnet with the wheel removed to demonstrate the Effect--but maybe it wasn't a magnet at all but just the metal tip of a pen--I don't remember? :) Someone closer to this technology will have to jump in.

Edited by Ratsneve
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For other GPSr's that have 2 or 3 axis electronic compasses will passing weak or strong magnetic fields hurt the compass in any way? Will it affect the compass calibration requiring recalibration? Is there any permanent damage?? How about over a prolonged period even near a magnetic source?

 

Could a magnetic field set off other problems like jumping off course or position hundreds of feet?

I doubt that weak transient magnetic fields will damage the compass. Strong is a relative term. My guess is that nothing you are going to run into in day to day use is going to cause damage.

 

I have no idea whether constant (as opposed to transient) fields would harm the magnetic element in the electronic compass. Safest to avoid them.

 

I don't know about recalibration after exposure to a magentic field. However, given the frequency with which the Colorado needs to be recalibrated anyhow, it certainly can't hurt to recalibrate.

 

And no, a magnetic field is not going to affect the reported position.

 

With regard to use in the car, unless you're that guy with subs that shake the entire car, I doubt that your speakers have anything to do with anything. On the other hand, there's lots of ferrous metal in the car. Proximity during calibration or use is going to affect the compass. I doubt that the electronic compass is any more sensitive than a normal pocket compass, though.

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Doesn't the Colorado have a small magnet in the rock-n-roller wheel?

I'm not certain now (another ten-year-old memory-fade) that the Hall Effect technology used has to use a permanent magnet but maybe just a ferrous material? Apparently, because I do remember reading a R-n-R thread not to long ago, you can use a small magnet with the wheel removed to demonstrate the Effect--but maybe it wasn't a magnet at all but just the metal tip of a pen--I don't remember? :lol: Someone closer to this technology will have to jump in.

There is no magnet in a Hall Effect sensor. I did a lab experiment to school to show that when you pass a current through a semi-conductor, like the silicon in a chip, a voltage will appear at right angles to the current if you apply a magnetic field(Hall Effect).
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There is no magnet in a Hall Effect sensor. I did a lab experiment to school to show that when you pass a current through a semi-conductor, like the silicon in a chip, a voltage will appear at right angles to the current if you apply a magnetic field(Hall Effect).

Well, that confirms what I thought I knew once about the Hall Effect and why moving the R-n-R around on a Colorado doesn't have any effect on an operational 2-axis compass. And we've speculated that there are too many accidental magnetic fields a GPSr might come across that it couldn't really cause any damage--nothing worse then recalibration.

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