25
Not Correct!
The measurement field of the probe is not completely
inside the material
Correct
!
The measurement field is completely inside the
material
When inserting the probe several times at the same place, there is the danger of segregation effects at this place.
By removing the probe out of the fresh concrete, the space will be filled with fine and liquid particles which could
lead to higher measurement values.
So it is important not to prick in the probe at the same place for several measurements.
5.2 Measurements of fresh concrete samples in a plastic bucket
It is necessary to perform a measurement of a fresh concrete sample in a plastic bucket because metal parts can
influence an electrical field. The bucket should be not too small, minimum should be around 12 liters and the
height should be large enough.
To avoid segregation, the fresh concrete inside the bucket should be not shaked. After insertion of the probe, the
concrete can be compacted only a little by stamping three times to the bucket, so that the concrete lies closed to
the probe´s surface at the dark ceramic plate.
It is recommend to carry out at least 4 to 5 measurements and take care to prick in the probe at different places
at the edge of the bucket, shifted by 70 to 90 deg.
