S
Stephen
- Jan 1, 1970
- 0
Hi,
I hope this isn't the stupidest question all week, but here it goes:
I'm trying to determine the relative permeability of a soft magnetic
material by measuring the inductance of a solenoid for which it is the
core material.
My simple plan was to saturate the core using a large permanent
magnet, measure the "air core" inductance, remove the magnet, and
measure the non-air core inductance. I then assumed (and this is
probably the stupid part) that the relative permeability of the core
material would simply be the ratio of these two measurements.
The material of the core in this case is Ni(45%)Fe(55%) whose relative
permeability should be well above 1000 if it was prepared correctly.
My measurements and calculations are giving a permeability value of
~10. Not good.
The core is simply a bar with its middle third wrapped with Cu wire,
and one third sticking out on each end. There is no closure path
other than air for the flux.
Can anyone out there steer me towards a web site where inductance for
such a structure can be calculated. Or if someone out there can
provide the calculations here, that would be even better.
Thanks in advance,
--Steve
I hope this isn't the stupidest question all week, but here it goes:
I'm trying to determine the relative permeability of a soft magnetic
material by measuring the inductance of a solenoid for which it is the
core material.
My simple plan was to saturate the core using a large permanent
magnet, measure the "air core" inductance, remove the magnet, and
measure the non-air core inductance. I then assumed (and this is
probably the stupid part) that the relative permeability of the core
material would simply be the ratio of these two measurements.
The material of the core in this case is Ni(45%)Fe(55%) whose relative
permeability should be well above 1000 if it was prepared correctly.
My measurements and calculations are giving a permeability value of
~10. Not good.
The core is simply a bar with its middle third wrapped with Cu wire,
and one third sticking out on each end. There is no closure path
other than air for the flux.
Can anyone out there steer me towards a web site where inductance for
such a structure can be calculated. Or if someone out there can
provide the calculations here, that would be even better.
Thanks in advance,
--Steve