To enable the field testing of sensors developed by the CENS Sensor group, a sample-preparation and data-acquisition system must be developed. We have found and tested compact, low power valves that use only 5.5mJ per switch, and have been combined into a fluidic multiplexer for calibration. We have made a potentiostat out of a few dollars of chips to replace a large bench top potentiostat that cost $20,000. We have designed a nitrate diffusion system to prevent clogs but still allow nitrate ions to diffuse. Finally, we have created a new board for sensor control and measurement that adds functionality to the previous board and corrects the errors of the old one.