Electric piezocones need to be de-aired before use. Standard piezocones with amplifier are relatively easy to de-air. The ELC10CFP and ELC15CFP type piezocones, the types without amplifier which are being used in combination with A.P. van den Berg data acquisition systems (like the iControl or Golog), require a so-called de-aerator in order to remove effectively the air from the pore pressure filter and fill up the pores with glycerine or silicone oil. The piezocone needs to be prepared before each test.
For this purpose Gouda-Geo developed a so-called de-aerator. The apparatus consists grosso modo out of 3 parts, i.e. the stainless steel frame on shock-absorbing supports, a high-end vacuum pump and a large, transparent vacuum vessel with strengthening rings. The vacuum vessel is covered by means of a stainless steel lid provided with stop-cock and pressure gauge. The unit is available with either a 230 Vac, a 24 Vdc or a 12 Vdc vacuum pump.
Its functioning is relatively straightforward. Fill the vacuum vessel with about 4 litres of glycerine. Prepare the electric piezocone as described in the relevant manual and place it tip down in the vacuum vessel. Make sure that the connector on top of the cone does not get wet. Slightly grease the O-ring of the lid with silicone containing grease and put the lid on top of the vessel. Open the stop-cock and switch on the vacuum pump. Let it run for some time until the required underpressure has been reached. Close the stop-cock and switch of the vacuum pump. The underpressure inside the vacuum vessel is kept and can be verified by means of the pressure gauge on top of the lid.
Technical Specifications
- Dimensions (L x W x H): 450 x 329 x 620 mm
- Weight: 16.4 kg
- Suitable for: ELC10CFP and ELC15CFP type piezocones
- Power supply: 230 Vac
- Volume of vacuum vessel: 8.5 litre
- Max. underpressure: – 0.8 bar
