A proper preparation of the piezocone and other equipment is paramount prior to CPTU testing in order to have good pore pressure response. The following components of the piezocone should be entirely saturated:
- The pore pressure filter
- The cavity between the pore pressure filter and the pore pressure sensor of the piezocone
- The housing of the pore pressure sensor
We recommend to use glycerine for saturating, since it is miscible with water. Other fluids, such as silicon oil, dematerialized water or a vegetable type of oil (for example sunflower or olive oil) can be used as well, but present specific problems that require special attention.
The saturation procedure consists of 2 specific stages, i.e. the de-airing of the pore pressure filters (mostly done in the office the day before CPTU testing) and the saturation of the << piezocone >> (mostly done in the field).