Electronic Alarms and Home Security Devices - Looking for very small sensor magnets

I just got new vinyl double hung windows. I have a Simon system with wireless surface mounted window contacts. The new windows have a very very very small sash on the top sash. My old sensors fit, but the magnets do not. I was thinking about buying the NX454 to replace my sensors, but I don't think those magnets will fit either.

I've read that it doesn't matter if you get a magnet from a different supplier than for the sensor itself. So, where can I find a replacement magnet that is no more than 1/4" wide?

I could always get a sensor for the top sash and bottom sash (two sensors per window), but I'd like to try and get the job done with one sensor on each window.

Any suggestions?

I'm not sure exactly how you want to mount the magnet/sensor. I also have vinyl double hung windows, but on mine only the bottom half lifts up. The top is fixed. I was looking to mount a magnet in the recessed portion above the the top sash where the brackets for the latch are mounted. The smallest magnets that I found, with the exception of a few rare earth magnets that were round, are the Amseco AMS10MG Mini Magnets. They are 1 1/4 Inch Long x 1/4 Inch W x 3/8 Inch D. For my windows, the recessed opening is 1/4 deep and 3/8 wide, so if I turn the magnets on their side they may just fit. At almost $4 a piece I am reluctant to order them when they may not fit. What dimensions do you need?

a magnet is pretty much a magnet as long as it is strong enough to provide sufficient force to deactivate (or activate, I guess it would depend on how you look at it) the window switch.

here is a site that sells neodyimium (rare earth) magnets. They are the strongest permanent magent you can get so using one smaller than another magnet of different construct shouldn;t be a problem. If you can get one a lot stronger than the OE it should reduce any false alarms as well.

notice they are quite inexpensive as well. There are several sites for this type of magnet as well.

http://www.gaussboys.com/magnets/cylinders/

http://www.rare-earth-magnets.com/SearchResult-CategoryID-21-KeyWords-Rod-All-True.html

search around those sites to find one that will fit your app. They come in all sorts of shapes and sizes.

Thanks for the links nap! I found some magnets that look like they may work, but how do you suggest mounting them to vinyl windows? The only way can think of is double stick tape, but I am concerned that they may come loose and or fall off eventually causing false alarms. Also it is safe to say that all of the magnets are much stronger the OE magnets? If this is the case, is the magnetic field also increased allowing for a slightly increased distance between the sensor and the magnet due to the magnet being thinner? I suppose the location of the poles will also come into play.

well, how were you intending on mounting the magnets you were considering purchasing?

I am not an alarm installer or tech but I would consider drilling the window frame and using a silicone adhesive, placing them. Be sure to not break the seal of a multi-pane window as it would cause irreparable damage to the window.

If you prefer to not drill the frame, I would suggest possibly the same silicone adhesive or some other type of mastic with good strength.

neodymium magnets are quite strong. Without knowing what type of magnet OEM was, it is impossible to compare but unless OEM was using neodymium magnets, it is safe to say that for a given size, the neo magnets are stronger.

The thinness of a magnet would actually reduce the guass (magnetic field) as compared to a thicker magnet. Size is everything when it comes to a magnet. The bigger the mass, the greater the gauss.

with a greater gauss, it would allow a greater distance but it would still be limited. I don;t remember exactly how it goes but something to the efffect that the strength of the pull diminishes exponentially as the distance increases.

which means yes, the attraction would be effective from a greater distance but that advantage is quickly reduced as the distance is increased.

I'm pretty sure this magnet would be strong enough.

http://www.unitednuclear.com/magnetfull4.jpg

btw, that is from another site that supplies neo magnets:http://www.unitednuclear.com/magnets.htm

if you have any of the magnets that you were using, you should be able to determine the amount of pull the have by lifting pieces of steel (smooth faced gives more accuracy) and weighing the weight lifted.

I'm not sure which of the sites I provided lists the pull of the magnets they sell but I remember one of them did list that spec.

Look for a magnet that is of the size you can use and compare the two lifts to determine if the neo magnet will work. That will also allow you to determine how small of magnet you can use that would provide the same pull as what you already have. Any magnet larger than that would of course provide more pull and therefore allow a slightly wider gap if that is an issue.

this magnet would be plenty large enough wouldn't it?

http://www.gaussboys.com/ndfeb-magnets/D7626.html

Notice that there are specs provided with this. (the pull for this mag is listed as 700 lbs). There is similar specs on this site for the other magnets they sell.