A proton precession magnetometer
Total price (material costs)
Hardware: Stable release, v2.2. License CC-BY-SA 2.0.
Software: Stable release, v1.3. GNU General Public License v3.0
An open source Earth's Field NMR Spectrometer
The PyPPM project includes a set of hardware and software designs that enable anyone to perform Nuclear Magnetic Resonance experiments using the Earth’s magnetic field.
There are two principal hardware designs in the PyPPM project. The first, PyPPMv1, is a Proton Precession Magnetometer that uses the non-adiabatic method of Russell Varian and Martin Packard to observe NMR signals at Earth’s field .
The second hardware design, PyPPMv2, is more appropriately termed an Earth’s Field NMR Spectrometer, as it adds the adiabatic polarization features required to perform more complex NMR experiments.
 M. Packard, R. Varian, Free Nuclear Induction in the Earth’s Magnetic Field, Physical Review, 1954, 93(4): 941.
1Institut Pasteur, Unité de Bioinformatique Structurale, Paris, France