deletions | additions       diff --git a/A_bottle_of_the_substance__.tex b/A_bottle_of_the_substance__.tex  index baa4cb7..7d60e22 100644  --- a/A_bottle_of_the_substance__.tex  +++ b/A_bottle_of_the_substance__.tex 
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A bottle of the substance on which NMR was being performed could be inserted into the center of the solenoid (Fig. \ref{fig:coils}). In this experiment, $H_{2}O$ was used. The parts of the apparatus which were key to performing the NMR are the solenoid, Helmholtz coils, and gradient coils, the magnetic field. \\\\  %All of these could be varied separately, as could the bandpass filter; they are discussed below. The solenoid with a coil constant of 15mT/A was used to apply a magnetic field to polarize the water. The magnetic field of the solenoid could be varied using a variable current input. The field of the Helmholtz coils, which artificially increased or decreased the Earth's magnetic field applied to the sample, was adjusted using a separate variable current input. The gradient coils could have changed the gradient of the magnetic field in the x, y, and z directions. In our experiment, the gradient coils were used to create a homogeneous field. \\\\  A bandpass filter, part of the NMR instrument, was used to restrict the frequencies to those around the Larmor precession frequency and to reduce and background noise such as 60 Hz fluctuations in the field due to fluorescent lighting in the room. \textbf{add information regarding the tuned amplifier} \\\\  In order to obtain the data, the oscilloscope measured the amplitude of the oscillating decaying signal, expressed as a voltage, which corresponded to the magnetization of the sample. The oscilloscope was also used to measure the Larmor precession frequency, which was measured over ten cycles. \textbf{screenshots?} \\\\  To summarize the electronics used, a simplified block diagram is shown in Fig.~/ref{fig:block}.