Ultra-low-cost manual soil respiration chamber

Soil respiration measurement is important to assess natural carbon dioxide production. The closed-chamber technique allows relatively easy soil respiration monitoring. A planned spatially large-scale campaign incites us to implement our ultra-low-cost portative chamber. The chamber itself is entirely built from commercial parts with little, easy-to-perform, quick machining work. The resulting setup is an easy-to-operate, standalone, robust device. The used sensors are cost-effective yet accurate digital sensors that were successfully checked against some reference sensors. All of these characteristics made the described chamber accessible to build and use for a wide scientific and educational community. In this short note, we describe this simple device along with its sensors and apparent respiration quotient tip.