In the geothermal energy sector, fluids are mostly sampled occasionally and manually. Especially in countries abroad, many geothermal surface manifestations like natural hot springs are situated in remote areas with restricted access causing a significant effort for sampling. The concentration of the solutes in the analysed fluid is not always reflecting its true chemical composition due to inappropriate sampling or inadequate sample storage before sending the sample to the laboratory. However, taking a duplicate sample is seldomly done due to time and money constraints.

A reliable sampling and sample storage as basis for reliable results is getting more and more important, also for geothermal projects in Germany where the mining authorities of some federal states request a groundwater monitoring in the surrounding of deep geothermal projects.

This was the reason to develop an innovative automated device for periodic sampling of fluids from springs and groundwater wells within the so called “GeoTief” project, implemented on behalf of the German Federal Ministry for Economic Affairs and Energy (BMWi) and funded by the Central Innovation Programme for SMEs (ZIM).

The automated sampling device AutoFluidSampler (GEO AFS) allows for a systematic, comparable and reliable acquisition of water samples in the frame of e.g. a long-term groundwater monitoring. Beside groundwater monitoring, the GEO AFS can also be used for tracer tests and long-term monitoring of earthquake and volcanic activity as well as in various industrial applications.

The regular sampling intervals of the GEO AFS can be programmed specifically to the individual needs or event-triggered in case a pre-defined threshold value (e.g. temperature or electric conductivity measured in the attached flow-through cell) is exceeded.

The GEO AFS offers the following advantages:

  • Event-triggered sampling for immediate preservation of evidence (text message on smartphone)
  • Samples taken and stored without air contact → reliable analysis of redox-sensitive ions
  • Pressure maintenance in sample bottles → no CO2 degassing
  • Optional addition of stabilizing chemicals (e.g. dosing of 1 ml concentrated HNO3 → reliable analysis of cations)
  • Constant sampling conditions → comparable results for reliable time series (no systematic error introduced by human factor and different sampling equipment)
  • Sample storage in darkness and e.g. at same temperature as in the aquifer (cooling or heating of sample housing via thermostat) → no precipitation due to temperature changes
  • Easy removal of the sample bottles which can be used for safe sample transport
  • Higher sample number → time series for improved interpretation of changes in composition compared to individual analyses (e.g. in case of anthropogenic contamination)
  • Only inert material in contact with sample (tailor made tubing and sample bottles on request)
  • Other tailor made accessories are available: flow-through measuring cell; additional filter; UV disinfection; security devices: GPS, spatial position sensor & earth anchor; grid independent power supply e.g. by fuel cell, mini-hydro, wind or solar power; remote control
  • Looked doors → no manipulation of samples and no harm to persons
  • All-weather resistant housing

For further questions please do not hesitate to contact us.
Your contact person: Dr. Michael Kraml

Please find below the product data sheet of the GEO AFS: