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A thermal equilibrium measurement (or TE) requires removing the beam and the microwaves, setting the pressure and temperature in the nose to be as constant as possible, and waiting for the NMR area to stabilize. The relaxation time of the polarization depends on the temperature, so the temperature is raised above 1K to decrease the time spent waiting. Even so, this will likely take as much as an hour per cup. The number and quality of the thermal equilibrium measurements directly affects the error on the target polarization measurement, so the TE should not be rushed! In experimental circumstances, the pressure to hurry and get back to taking beam can result in sloppy TEs which adversely affect the experiment's systematic error. Take time to be accurate; time has been budgeted to allow for these TE measurements.
The NMR (Nuclear Magnetic Resonance) system is needed to measure the polarizationof the sample.