Sensitivity; Antenna Mark - JRC Handy Search NJJ-95B Instruction Manual

3.2.3 Sensitivity

When the power is turned on, sensitivity is set to "A shallow". "A shallow" is a sensitivity setting that
is applicable to the detection of rebar with a depth of less than 10 cm in general concrete.
"A" of "A shallow" indicates the overall sensitivity; "shallow" indicates depth sensitivity.
There are five levels for overall sensitivity: "-2, -1, A, +1, +2." In general, use the unit in the "A"
setting. Use the +side to increase sensitivity and use the –side to reduce sensitivity.
There are two levels for depth sensitivity: "shallow and deep." Select "shallow" when the object to
be probed is at a depth less than 10 cm. Select "deep" when the object to be probed is at a depth of
10 cm or more.
To change the sensitivity, press 3 GAIN . The sensitivity is changed as follows:
A, shallow → +1, shallow → +2, shallow → -2, deep → -1, deep → A, deep → +1, deep →
→ +2, deep → -2, shallow → -1, shallow → A, shallow → +1, shallow →
Remarks
• To change sensitivity for scanning results, press 3 GAIN after scanning.
If sensitivity is changed after scanning, the unit uses the new sensitivity for the next
scanning.
For the changing of sensitivity after scanning, see "Section 3.3.2 Sensitivity Switching."

3.2.4 Antenna Mark

If core-boring or reinforced rebar locations are known beforehand (shown on a
construction diagram) the NJJ-95B can mark the locations by placing an "Antenna Mark"
at the applicable places during scanning.
The method of use for this antenna mark is shown below.
a) Place the 14
over the sense test line.
b) Press 9 START. After about one second, a short single buzzer sound is generated, the
fixed cursor is displayed at a position of about 10cm of the movement distance scale on the
B mode screen, and then scan test preparation is complete.
c) Move the unit on top of the scan test line at a speed of less than 40 cm/s by rotating the
wheels. If speed exceeds 40 cm/s, a buzzer sounds and the data for that timeframe is
invalid. Please perform the scan test again.
d) Push 10 MARK when the 14
core-boring as based on design blueprints. (A ▼ is shown on the movement distance
gauge)
e) Press 9 START again to finish. A double buzzer sound is generated and the scan test is
on the side of the unit over the start line and the forward/backward 14
on the side of this unit overlaps the rebar position or
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