After having great success with the laboratory multi-chamber soil respirometer system, we built a portable version that could be deployed in the field for in-situ measurements. It still uses the same Licor LI-840 gas analyzer system and a smaller Arduino controller, based on the Sparkfun ArduinoPro board since it has better power efficiencies than the Uno, which is important for battery-powered operation. Data is still displayed on an LCD screen and recorded to an SD card. The Arduino controls 3 pairs of solenoids, and a small circulation pump provides the air flow through the remote chambers and through the gas analyzer. The entire control and measurement system is mounted in a waterproof toolbox, and the air and power connections go through bulkheads in the case wall. It is powered by a set of deep-cycle marine batteries mounted in a separate case.