2
Donald G. Hil , Ph.D., R.Gp, R. G., R.P.G., L.P.Gp.
dgh@hil petro.com
PTE-461:
Fal 2007
Section 5:
Resistivity
Slide No.:
4
Magnetic Properties and
Magnetic Field Vectors
•
Force, F, Magnetic Field
Intensity, H, Magnetic
Induction, B, Magnetic
(macroscopic) Polarization,
M, and Magnetic dipole, m,
are all vectors (first rank
tensors) and are directional.
•
Magnetic permeability,
μ
,
and relative magnetic
permeability,
±
m
, are second
rank tensors and are
directional.
Donald G. Hil , Ph.D., R.Gp, R. G., R.P.G., L.P.Gp.
dgh@hil petro.com
PTE-461:
Fal 2007
Section 5:
Resistivity
Slide No.:
5
Circuit Element Analogues
• Resistance:
– linear response
– current is in phase with
voltage
• Capacitance:
–
Current
opposes
voltage
changes
– Current
lags
voltage
• Inductance:
–
Voltage
opposes
current
changes
– Current
leads
voltage
Donald G. Hil , Ph.D., R.Gp, R. G., R.P.G., L.P.Gp.
dgh@hil petro.com
PTE-461:
Fal 2007
Section 5:
Resistivity
Slide No.:
6
Disk-Shaped Measurement Sample
• Current density is
distorted at sample
edges
• Sample geometrical
factor is given by:
G
=
S
'
L
±
²
³
´
µ
¶
where:
S’ is the electrode
area, corrected for
E
distortion, at the edges