Operation Manual for ZBL-R620/R630 Rebar Locator
Fig. 2.7 Pre-Scanning
In order to know the rebar’s general distribution a
pre-scan may be performed on the concrete element. It is an
important part when selecting scan starting point. A pre-scan
allows real-time display of test information without saving
data.
Generally, the rebars of the top layer are located first, and
then a measurement of the central point between two top layer
rebars is needed in order to locate lower layer rebars.
1) Rebar Location (Fig. 2.7, also see video)
Put the probe on the surface of the concrete element;
ensuring that the probe is parallel to the rebar. Be sure to move the probe smoothly and
evenly in a uniform motion. When the probe moves closer to the rebar, the signal strength
bar rises, the signal value is larger, and the concrete cover thickness value becomes
lower; once the peak value has been reached the instrument will produce a “beep” sound,
and the screen displays related information. The display style differs according to the
different scan mode.
T
o accurately determine the peak of the signal move the probe in the opposite
direction until the signal value is largest, and the thickness is the lowest. The central line
of the probe is then the accurate location of the rebar. Select the central location of the
two rebars which have largest distance between each other as the starting point of
scanning. (Please mark this point with a pen)
2) Rebar Direction (Fig. 2.8, video)
The direction of rebars can be detected by the
following two methods.
When the rebar location is known, rotating the
probe directly on the rebar. When the signal
value is the largest and the thickness value is
the smallest, the direction of the probe is the
direction of the rebar.
Detect two rebars location along two parallel
measuring lines, the connected line between the
two locations is then the direction of the rebar. (See fig. 2.8)
3) Estimate the rebar diameter
When the probe is located directly on the rebar, and is parallel to the rebar.
Press
【↑】
key, the screen displays the rebar diameter and the concrete cover
thickness.
Note: There is a black triangle symbol before the thickness value; it means the thickness
does not correspond to the pre-set diameter.
In abnormal testing conditions, the rebar diameter may not be measured.
2.6.2 Start Scanning (Save Scanning)
Put the probe in the scan starting point as determined by the pre-scan, move the
probe, the test result may vary with the probe location
1) General Test
Fig. 2.8 Rebar Distribution
Test Line 1
Test Line 2
