A method for improving the precision of time domain low field H-NMR analysis, the method comprising rotating a sample within a RF coil and acquiring multiple time domain signals for the sample at multiple orientations within the RF coil. A drive shaft, located upstream of the printhead, has a longitudinal axis, a first radius over a central length, and a second radius less than the first radius at a first recess and a second recess. Furthermore, the optical article includes an electrically responsive layer having a first surface and a second surface, wherein the electrically responsive layer is characterized by an optical absorbance in the range of about 200 nm to about 800 nm. A preferred method of using this invention employs a multi-component approach that permits long-term storage of the components in a stable, concentrated form. The chamber may receive a first portion of the gas through the first hole and a second portion of the gas through the second hole.