PSA: cell phone demagnetized my hotel room key card

[brainhulk]

i went to go work out and just brought my room key card inside my cell phone holder. Get back to my room and the key doesn't work anymore...

can it demagnetize other cards too?

 

[Ichinisan]

i went to go work out and just brought my room key card inside my cell phone holder. Get back to my room and the key doesn't work anymore...

can it demagnetize other cards too?

Need more evidence than that before I'll believe it.

 

[Llwellyn]

i went to go work out and just brought my room key card inside my cell phone holder. Get back to my room and the key doesn't work anymore...

can it demagnetize other cards too?

It wasn't the cell phone, it was the case. It probably has a magnetic clasp, or an "I'm docked" magnet in the base if it's for a Blackberry or other phone that is set up that way.

I'm an issuing authority for my institution's ID badges, and I have heard this quite a bit, and they always blame the phone. I have them show me the case, and inevitably I can show them the magnet. Haven't had a demagnetized card yet that didn't have a magnet involved.

It's not possible for the low power RF of the cellphone to degauss the magstripe on anything. Even a low-co magstripe is a few hundred Oersted, and most of the hotel keycard types are hi-co these days at around 3000 Oersted.

The problem is a lot of these new rare-earth type magnets that are in cases and that people like to buy and play with are so tiny, but have huge Gauss ratings. I've seen some neodymium magnets the size of a dime that have close to a 10K Gauss rating. Get that near a magstripe on any type of card, and kiss the encoding goodbye.

 

[Rubycon]

It wasn't the cell phone, it was the case. It probably has a magnetic clasp, or an "I'm docked" magnet in the base if it's for a Blackberry or other phone that is set up that way.

I'm an issuing authority for my institution's ID badges, and I have heard this quite a bit, and they always blame the phone. I have them show me the case, and inevitably I can show them the magnet. Haven't had a demagnetized card yet that didn't have a magnet involved.

It's not possible for the low power RF of the cellphone to degauss the magstripe on anything. Even a low-co magstripe is a few hundred Oersted, and most of the hotel keycard types are hi-co these days at around 3000 Oersted.

The problem is a lot of these new rare-earth type magnets that are in cases and that people like to buy and play with are so tiny, but have huge Gauss ratings. I've seen some neodymium magnets the size of a dime that have close to a 10K Gauss rating. Get that near a magstripe on any type of card, and kiss the encoding goodbye.

Some speakers in cell phones use rare earth magnets and the leakage could be strong enough to damage magnetic strips. The cases definitely can. That goes for any case or accessory that haves a magnetic clasp or catch.

 

[brainhulk]

hmmmm, totally forgot about the magnets in the case. yeah, i bet the magnet in a cell phone can do it too. but there is two magnets that keeps the flap closed on the cell phone case that i'm betting were the one's that did it.

...

 

[olds]

It's the phone. My Evo does it too.

 

[dmcowen674]

cell phone demagnetized my hotel room key card

i went to go work out and just brought my room key card inside my cell phone holder. Get back to my room and the key doesn't work anymore...

can it demagnetize other cards too?

1900 MHZ is close to microwave.

Put any card in a microwave for just a second or two and same thing will happen so no surprise putting cards together with phone in holder over long term exposure wipes it out.

 

[Xcobra]

1900 MHZ is close to microwave.

Put any card in a microwave for just a second or two and same thing will happen so no surprise putting cards together with phone in holder over long term exposure wipes it out.

Lies... ()

 

[God Mode]

Just kick the door down for what you paid like a true American. You don't need no stinkin key.

 

[PsiStar]

More likely the hotel screwed up ... happens occasionally to me & the cell is not near the key card.

To put it another way, how do you know the hotel did not screw up?

 

[iGas]

My phone did that to my hotel cards before.

 

[DrPizza]

1900 MHZ is close to microwave.

Put any card in a microwave for just a second or two and same thing will happen so no surprise putting cards together with phone in holder over long term exposure wipes it out.

Uhhhhhhh, no.


What Llwellyn said. I can't count the number of cards I've erased with neodymium magnets in my pockets (it's an annual mistake when I'm teaching about magnetism in physics class.)

 

[Murloc]

electronic car keys can discharge a mobile phone if you keep them together in the pocket apparently. True story or fake?

 

[cronos]

It wasn't the cell phone, it was the case. It probably has a magnetic clasp, or an "I'm docked" magnet in the base if it's for a Blackberry or other phone that is set up that way.

I'm an issuing authority for my institution's ID badges, and I have heard this quite a bit, and they always blame the phone. I have them show me the case, and inevitably I can show them the magnet. Haven't had a demagnetized card yet that didn't have a magnet involved.

It's not possible for the low power RF of the cellphone to degauss the magstripe on anything. Even a low-co magstripe is a few hundred Oersted, and most of the hotel keycard types are hi-co these days at around 3000 Oersted.

The problem is a lot of these new rare-earth type magnets that are in cases and that people like to buy and play with are so tiny, but have huge Gauss ratings. I've seen some neodymium magnets the size of a dime that have close to a 10K Gauss rating. Get that near a magstripe on any type of card, and kiss the encoding goodbye.

Wow thanks, this explains a lot. My wife has this purse with all kinds of magnetic clasp thingy and she almost always had key cards demagnetized on her. We have always thought it was her phone (the receptionist at the hotel usually mentioned cell phone as well), and she tried to put the card away from the phone but it kept happening, while I never had any problem with it.

 

[SaDiZTiKStyLeZ]

Carry it in your butt next time.

 

[Rubycon]

1900 MHZ is close to microwave.

Put any card in a microwave for just a second or two and same thing will happen so no surprise putting cards together with phone in holder over long term exposure wipes it out.

First of all microwave oven frequency is 2450 MHz which is not close and secondly the power in the oven cavity is many, many times higher. Your comparison is like comparing a laser pointer to a 10W 1064nM laser!

Google "play store" has an app called metal detector that uses the flux sensor in the phone (which provides magnetic compass functionality). This will show you have powerful these magnets are!

 

[EagleKeeper]

More likely the hotel screwed up ... happens occasionally to me & the cell is not near the key card.

To put it another way, how do you know the hotel did not screw up?

I have an Evo phone.
I had the hotel cut two card keys are the same time.
One kept in the wallet.
the other in the pocket where I keep the cell phone.

A couple of days later, the non-wallet would not work.
the one in the wallet worked until the programmed date.

 

[BrokenVisage]

Carry it in your butt next time.

Then you have to worry about EMP farts!

 

[alkemyst]

just go to the fucking front desk.