Measuring change of magnetic field strengh over distance

  • #1
april7
4
0
I have few cylindrical neodymium magnets of same diameter and different heights and different magnetic inductions in the geometric center of the magnetic pole surface. Knowing those values of magnetic induction, how can I measure what the induction is at a certain distance from that center?

For example height: 4 [mm] and induction: 0,263 [T]
What equation do I use to know what the induction is at distance of 4mm? I'm very much clueless about magnets and don't really know where to look.
 
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  • #2
Get a Hall probe.

Trying to measure the field with another magbet is difficult, as each pole responds differently, and what you will see is the difference in the field between the two. Converting that to a field is non-trivial.
 
  • #3
april7 said:
I have few cylindrical neodymium magnets of same diameter and different heights and different magnetic inductions in the geometric center of the magnetic pole surface. Knowing those values of magnetic induction, how can I measure what the induction is at a certain distance from that center?

For example height: 4 [mm] and induction: 0,263 [T]
What equation do I use to know what the induction is at distance of 4mm? I'm very much clueless about magnets and don't really know where to look.
Do you want to measure the magnetic field or calculate it? If you are "very much clueless about magnets" I suggest that you buy a magnetometer and measure it. There are apps for smartphones but I am not sure of their limitations for strong magnetic fields like yours. Also, bringing a neodymium magnet close to your smartphone might mess up its compass calibration or other "stuff".
 
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  • #4
kuruman said:
Do you want to measure the magnetic field or calculate it? If you are "very much clueless about magnets" I suggest that you buy a magnetometer and measure it. There are apps for smartphones but I am not sure of their limitations for strong magnetic fields like yours. Also, bringing a neodymium magnet close to your smartphone might mess up its compass calibration or other "stuff".
Yes, I haven't specified it but I need to calculate it
 
  • #5
april7 said:
I need to calculate it
april7 said:
I'm very much clueless about magnets
Those two statements are mutually inconsistent.

What you want is very difficult and usually solved numerically. It is not for the clueless, I'm afraid,
 
  • #6
Vanadium 50 said:
Those two statements are mutually inconsistent.

What you want is very difficult and usually solved numerically. It is not for the clueless, I'm afraid,
I'm doing my engineering thesis on superparamagnetic iron oxide nanoparticles (SPION) and I'm tasked with creating a model of magnetic pad we will use to stimulate particles with. I have to calculate which of few different neodymium magnets will give approximate value of 200 mT at distance of 4 mm. I want to know if I can calculate it and how I can do that without using programs.
 
  • #7
Again, this is really hard. You don't even have adequately specified boundary conditions. As people have suggested, measure.
 
  • #8
well I used chatgpt, asked same question and was directed to online calculator and softwares that can calculate it
I've got my answer now so I guess thread can be closed
 
  • #9
Good luck.
 

Related to Measuring change of magnetic field strengh over distance

What is the relationship between magnetic field strength and distance?

The strength of a magnetic field typically decreases with the square of the distance from the source. This relationship is described by the inverse square law, which states that the magnetic field strength is inversely proportional to the square of the distance from the source. For a point source, the magnetic field strength \(B\) at a distance \(r\) is given by \(B \propto \frac{1}{r^2}\).

How can I measure the change in magnetic field strength over distance?

To measure the change in magnetic field strength over distance, you can use a magnetometer or a Gaussmeter. Place the sensor at various distances from the magnetic source and record the magnetic field strength at each point. Plotting these values will allow you to observe how the magnetic field strength changes with distance.

What factors can affect the measurement of magnetic field strength over distance?

Several factors can affect the measurement of magnetic field strength over distance, including the presence of other magnetic fields, the medium through which the magnetic field is passing (such as air, water, or metal), and the accuracy and sensitivity of the measuring instrument. Environmental noise and interference can also impact the readings.

Why does the magnetic field strength decrease with distance?

The magnetic field strength decreases with distance because the magnetic field lines spread out as they move away from the source. This spreading causes the field strength to diminish. The inverse square law quantifies this effect, showing that the field strength is inversely proportional to the square of the distance from the source.

Can the change in magnetic field strength over distance be used to determine the source's location?

Yes, by measuring the magnetic field strength at multiple points and analyzing how it changes with distance, you can triangulate the position of the magnetic source. This method is often used in geophysics and other fields to locate magnetic anomalies or sources.

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