What is in the unwired side of a door contact sensor?

[VogonPoet]

I've bought some magnetic door sensors (CQR SC570) but the lip of the upvc doors I want to fit them on is as thick as the sensors themselves. If I screw the unwired side on the face of the door it won't actually line up with the part screwed to the door frame when the door is closed, it'll be raised above by the thickness of the door.

Looking inside the unwired part of the sensor it is filled with black epoxy with a small raised square in the middle. Is it just a magnet in there or is the epoxy covering something else as well?

If it is just a magnet perhaps I could cut it out of the sensor housing and rebate it into lip of the door - I'll just dremel out a small square of plastic from the edge of the door and epoxy the magnet into the hole. Then I could fit the detector part so it lines up with the magnet.

As long as I get the magnet in the same orientation as when it was in the housing, and the distance between the two is similar, it shouldn't make any difference to the sensor, right?

 

[ironsidebod]

It is just a magnet, and yes keep the orientation the same (some contacts are more sensitive than others) and it'll be fine.

 

[JohnD]

sometimes you need to pack out underneath the sensor or magnet to line them up, and use longer screws. You can buy plastic packing wedges, or fabricate something, but filler or silicone will do as long as it is something that will not crack and fall out. If the sensors are above eye level people will not notice. Wrap the sensor or magnet in cling film so it does not stick to the filler or silicone in case it needs to be removed in future.

 

[VogonPoet]

Thanks for your replies, I'll give it a go.