A system for determining polarization of a gas comprises a container that
contains the polarized gas. An oscillator circuit comprises an Nuclear
Magnetic Resonance (NMR) coil that is positioned adjacent to the
container. A pulse generator circuit is configured to generate an
electrical pulse that may be transmitted to an optical cell through the
NMR coil to excite the polarized gas responsive to a control processor. A
Q-reduction circuit that is independent of the pulse generator circuit is
configured to reduce oscillations in the oscillator circuit from the
transmitted electrical pulse responsive to the control processor. A
receive circuit is responsive to an electrical signal that is induced in
the oscillator circuit due to the electromagnetic excitation of the
polarized gas. The control processor is configured to determine the
polarization of the gas based on the output signal of the receive
circuit. A polarimetry circuit for determining polarization of a gas
includes an NMR coil that may be configured to excite a polarized gas and
be responsive to an electromagnetic signal generated by the excited,
polarized gas. The polarimetry circuit has a reproducible polarization
measurement variability of less than 2% when the NMR coil is exposed to a
temperature in a range of about 0.degree. C. to about 200.degree. C.
Moreover, circuit-to-circuit polarization measurement variability may be
less than about 3%.