50.1.1 z. Vertical component of the earth's magnetic field,
as used Z is-the simulated vertical component of the earth's
magnetic field. Z is a fixed value that is time invariant.
50.1.2 Core sensitivity. The amount of filtered, amplified
signal the core will pick up as a 14 turn magnetometer (formed
when a core is placed-in the test fixture which provides the
magnetic environment for the test circuit of Figure 1) from the
calibrated 10 hertz sinusoidal signature present in the test
50.1.3 Core linearity. The percentage difference between the
core sensitivity at O-bias (Z = O oersted) and N-bias (Z= +.450
oersted) or S-bias (Z = -.450 oersted)
50.1.4 Bias coils. The set of Helmholtz coils that provide
the DC magnetic field (Z) for determining the DC magnetic offset
for the 10hz magnetic signature.
50.1.5 Drive coils. A secondary set of Helmholtz coils that
produces the 10 hz magnetic signature.