closed, airtight system, which minimized atmospheric interaction. An overflow
tube from each sonde was connected to a sampling container fitted with an airlock.
Composite samples were collected monthly from this container for geochemical
analysis.
The sondes were dismantled in 2011 due to problems with maintaining and
calibrating the sensors and the monthly replacement of batteries. The pH and DO
sensors required more frequent calibration than was practical for this project and
were also subject to fouling. For example, calcite precipitated on the DO membrane, resulting in unreliable measurements. For the purposes of the James Cave
project, these parameters were of lower level importance, but if pH and DO are
Fig. 7 Current dripwater site instrumentation. Sarah Eagle in background (Source: Author)
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tube from each sonde was connected to a sampling container fitted with an airlock.
Composite samples were collected monthly from this container for geochemical
analysis.
The sondes were dismantled in 2011 due to problems with maintaining and
calibrating the sensors and the monthly replacement of batteries. The pH and DO
sensors required more frequent calibration than was practical for this project and
were also subject to fouling. For example, calcite precipitated on the DO membrane, resulting in unreliable measurements. For the purposes of the James Cave
project, these parameters were of lower level importance, but if pH and DO are
Fig. 7 Current dripwater site instrumentation. Sarah Eagle in background (Source: Author)
218
M.E. Schreiber et al.