The device used to collect all of the data shown above was built in a form most suitable for a teaching lab, as that is its intended use. The transmitter and receiver were constructed on a single 5 x 16 cm breadboard, while the polarization coil driver, due to the high current handling required of its components, was soldered together on a prototyping board. With a little effort at packaging the device in a robust manner, it could easily be configured for regular use in the field. It is small enough to be transportable in a single trip by bicycle. The transmitter/receiver combination draws a total of 16 mA from its supplies, making it suitable for battery powered operation, two 9V batteries would suffice for 20 hours. The Arduino board is powered by its USB connection to a notebook computer. The computer power supply for polarizing the nuclei however requires on the order of 100 W. This requirement is easily met with a modest lead acid battery and inverter. Alternatively, the polarization coil could be powered directly from such a battery, either with the coil connections in parallel for a 6V battery, or in series for a 12 V battery. A 6 V 12 A-hr sealed lead acid battery has a mass of < 2 kg (e.g. Panasonic LC-R0612P, available from Digi-key), and two of these in parallel could power the polarization coil at 50% duty cycle for more than two hours.