The GeoN Probe and the GeoN Filter Tip
A GeoN Filter Tip is connected to an extension pipe. Installation is performed by pushing, hammering or by pre-drilling. The typical installation depth is 5-30 meters but tips have been installed as deep as 300 meters.
A flexible rubber disc in the filter tip prevents water from entering the extension pipe; it is only the filter tip that contains water. Today, there are six types of GeoN filter tips, all specially designed for a specific test purpose.
Certain tips are used for measurements of pore pressure and permeability, other for groundwater sampling. Depending of the kind of test, tips are installed permanently or are removed directly after testing.
A GeoN Probe (sampler, pressure transducer or permeameter), connected to a wire or a cable, is lowered down through the pipe until it reaches the filter tip.
All GeoN probes include a hollow hypodermic needle that will penetrate the rubber disc in the tip. After penetration, the probe is connected to the aquifer and the test can begin. After the test, the probe is pulled up and the connection to the aquifer is automatically closed.
The hypodermic needle and the rubber disc, the needle connection, is a totally leak proof quick connect to the aquifer. The disc can be penetrated hundreds of times and still, it will be totally tight when the needle has been retracted.