
Fundamentals of Magnetic Measurements 95
If the H-coil sensor is not exactly placed on the surface
of the sample (e.g., due to the thickness of the sensor
itself), it is possible to use more than one coil and then to
extrapolate the result to the sample surface (Tumanski
2002). Nakata proposed to use a system of two H-coils
for improvement of measuring accuracy of magnetic
eld strength (Nakata et al. 1987).
When we measure the ux density in the sample, we
are usually able to determine the cross-sectional area
quite accurately. Because the thickness of the sample
can be varying in the length l, we can determine the ...