Table 2.

Bi-planar coil characteristics: theoretical results for each coil are shown with measured values in brackets. The calculated values of resistance assume that 0.56 mm diameter copper wire was used in coil construction.

Coil	Length of wire ($\mathit{m}$)	Resistance of wire ($\mathit{\Omega }$)	Coil Strength ($\mathit{nT}/mA$ or $\text{nT}/\text{m}/\mathit{mA}$)	Inductance ($\mathit{\mu H}$)
${\mathit{B}}_{\mathit{x}}$	170	11.9 (14.2)	1.21 (1.13 ± 0.1)	544 (619)
${\mathit{B}}_{\mathit{y}}$	170	11.9 (13.3)	1.21 (1.06 ± 0.1)	544 (614)
${\mathit{B}}_{\mathit{z}}$	186	13.0 (13.8)	7.29 (7.90 ± 0.3)	1520 (1290)
$\mathit{d}{\mathit{B}}_{\mathit{x}}/\mathit{dz}$	195	13.7 (16.1)	6.75 (6.50 ± 0.2)	843 (985)
$\mathit{d}{\mathit{B}}_{\mathit{y}}/\mathit{dz}$	195	13.7 (15.5)	6.75 (6.33 ± 0.6)	843 (984)
$\mathit{d}{\mathit{B}}_{\mathit{z}}/\mathit{dz}$	168	11.8 (12.8)	14.4 (14.0 ± 1.0)	968 (1090)