The determination of range correction values di
showed high
variations, especially for concrete where values between 0.4mm
and 10.1mm had been calculated. Repeated measurements led
to quite different results. The reason for this phenomenon could
be the specific surface structure of the material as Thiel and
Wehr (2004) observed anomalous effects for phase shift
scanners at micro structures of a quarter of the wavelength
within the instantaneous laser spot. Therefore, additional test
series with other test plates of concrete have to be carried out.
The estimated range correction values for the other materials are
sampled in Tab. 4. An error propagation confirmed that there is
a great uncertainty for these values.