© 2014 Proceq SA
26
Midpoint line
CL
16
MC (SLA)
14
Correct probe position
indication on display
Ideal: Both
rectangles
full and
green
Figure 28:
Correct Probe positioning for diameter measurements
The diameter displayed for the settings “Metric”, “Imperial” and “Japa-
nese” are shown in Appendix A1.
NOTE! When measuring a diameter on rather old structures
set the unit “Metric” and convert the displayed diameter from
Millimeter to the “Imperial” or “Japanese” bar size if neces-
sary.
Rebar diameter determination in rather thin slabs:
In thin slabs the rebar mesh of the opposite side may be too close and
will affect the rebar diameter measurements. In those cases the meas-
ured diameter is too high.
Figure 29:
Rebar diameter measurements on thin slab
Line-Scanning on Different Rebar Arrangements
Single-Line, Multi-Line and Area-Scanning are mainly done to measure
and show the cover values along a long line, respectively on a large area.
However, for accurate cover readings the diameter must be measured
first, thus on each different rebar arrangement. The measured diameter is
to be set prior to scanning the cover. Therefore it is advisable to open for
each area of different rebar arrangement a separate test file and to scan
over rebars only with the same measured rebar diameter.
upper part single rebars
lower part overlapping rebars
For example: To scan a wall of a cut and
cover tunnel section at least two test files
must be opened. One for the lower part
with overlapping vertical rebars with a
larger diameter measured, one on the up-
per part with single vertical rebars, (see
Figure 31).
Figure 30:
Line scanning on different rebar arrangements
D
s
~
1.4 D
r
C
D
s
D
s
= Set Diameter
Real Diameter D
r
In case the diameter can-
not be measured the re-
bars should be exposed
in one area. The diameter
to be set is in general 1.4
times the real diameter of
a single bar.
Figure 31:
Measured diameter D
s
at overlapping areas
