Automated chamber systems
Automated chamber systems are useful tools in the investigation of soil-atmosphere trace gas exchange and its response to changes in environmental conditions. Since monitoring takes place quasi-continuously (several measurements a day), these systems permit accurate surveillance of temporal dynamics of trace gas emissions and reliable detection of short-lasting events which may be missed by manual sampling methods.
In the automated chamber systems developed at Karlsruhe Institute of Technology (IMK-IFU), the whole automated chamber system is controlled by sampling and recording units using data logging modules and relays. The main components of such systems are chamber blocks, control units, gas analyzers, and environmental monitoring units.
How does it work?
Chambers are arranged in pairs that close and open simultaneously with pressurized air applied to the lids, and gas samples are taken sequentially from all chambers. Within each measurement cycle, this procedure is repeated once per chamber block of the system. Monitoring takes place quasi-continuously with several measurements recorded daily. Gas chromatographs (ECD and FID detectors) are used to investigate N2O, CH4, and CO2.
In addition, a set of probes measures continuously environmental parameters–for instance, soil temperature, soil moisture at different soil depths, and precipitation. Data are stored by data logging modules.
Chambers closing period and gas sampling temporal sequence–as well as the size and shape of the chambers–depend on the investigated ecosystem and the trace gasses of interest.