Altering Magnetic Field Strength at a Radius
Altering Magnetic Field Strength at a Radius
(OP)
Hello,
Please forgive my lack of knowledge on magnetism. I have an application in which I need a ring magnet of fixed strength on a piston to trip a sensor (reed switch) a certain radius away from the axis of travel (greater than the OD of the magnet). The sensor requires a field strength of a certain range. If I need to keep the sensor location fixed, can I tweak the Gauss it sees by placing another ring of steel (or aluminum or stainless) around the magnet? Will this redirect the field lines more through the outer ring and less through free space where the sensor is? The magnet is described as being axially magnetized, N42.
Please forgive my lack of knowledge on magnetism. I have an application in which I need a ring magnet of fixed strength on a piston to trip a sensor (reed switch) a certain radius away from the axis of travel (greater than the OD of the magnet). The sensor requires a field strength of a certain range. If I need to keep the sensor location fixed, can I tweak the Gauss it sees by placing another ring of steel (or aluminum or stainless) around the magnet? Will this redirect the field lines more through the outer ring and less through free space where the sensor is? The magnet is described as being axially magnetized, N42.
RE: Altering Magnetic Field Strength at a Radius
Nevertheless, there's not much you can do to concentrate the field as you describe. Putting something at the sensor end might possibly improve things.
TTFN (ta ta for now)
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RE: Altering Magnetic Field Strength at a Radius
A sketch would help a lot.
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RE: Altering Magnetic Field Strength at a Radius
Aluminum or austenitic stainless won't have an effect, while martensitc or ferrite stainless are ferromagnetic.
RE: Altering Magnetic Field Strength at a Radius
RE: Altering Magnetic Field Strength at a Radius
Yes magnetic shielding does exist. you can have a design to even shield all magnetic flux, with zero Guess going through the sensor.
RE: Altering Magnetic Field Strength at a Radius
Yes, the sensor is located some radius away from the magnet's axis of travel so that when the piston reaches a certain linear position, the sensor is tripped.
Since there is a piston cap above the magnet (not seen in the sketch), I am thinking of stacking ferritic rings as needed around the magnet (thinner than or equal to the magnet thickness itself) to redirect some of the flux and lessen the field the sensor sees. Am I understanding correctly?
I did not know about the shielding, sources I read said otherwise but then that's why I also came back to this website.