OPERATING MANUAL
30
2.3. Operational check with test dummies
Once ST 40
2
Cayman has been adapted to the environment, its functioning should be checked
with the aid of test dummies that imitate nonlinear materials (1, Fig. 1).
For that purpose select an area free of responses from nonlinear elements or reflecting
surfaces, and place there the dummy that is marked red.
Press button
(3, Fig. 7) repeatedly to set the receiver gain at 3 lit segments of the
TUNING indicator, which corresponds to medium sensitivity.
Point the antenna at the test dummy and find the distance at which all the 16 segments of the
INPUT LEVEL Gauge bar 1 light up. For a device that is in proper working order and has self-
tuned properly, this distance should be no less than 0.8 m.
Repeat the procedure using the dummy with the blue marking. In doing so, find the distance
at which all the segments of the INPUT LEVEL gauge bar 2 will be lit. For a properly working
device that has been adjusted to the environment, this distance should be no less than 0.3m.
If either distance is found to be smaller than the respective value above, it is advisable to
engage the self-tuning routine anew (see 2.2) and repeat the checks as described above.
If both distances exceed the required minimums, the device is functional and operation-ready.
2.4. SEARCH Mode
Once ST 40
2
Cayman has been prepared and proven functional as described above in 2.1 –
2.3, it can be put to use. When activated, the device starts up in SEARCH mode, and the receiver
gain is by default set to maximum, which is displayed by 5 lit segments of the TUNING indicator.
The SEARCH mode is the primary operation mode for ST 400. The operator can change the
receiver gain at his discretion, thus increasing or decreasing the detection range.
The gain can be varied discretely with an 8dB increment, over 5 values in a 40dB range; each
increment corresponds to one LED segment of the TUNING indicator. Thus, if all five are lit, the
gain is equal to 40dB, providing maximum detection range. If all are dimmed, the gain is 0dB,
with minimum detection range. The gain can be brought a step up or down by a single pressing of
the TUNING buttons or (1 and 3, Fig. 7).
Levels of return signals from a target area are shown in the three INPUT LEVEL multi-
segment LED gauge bars (Fig. 4: 4–6).
INPUT LEVEL led gauge bar 1 (16 red LEDs) displays the levels of return signals from
semiconductor material. The indication is accompanied with an alternating sound alarm.
INPUT LEVEL led gauge bar 2 (16 blue LEDs) displays the levels of return signals from
MOM (metal/oxide/metal) structures.
INPUT LEVEL led gauge bar 3 (16 white LEDs) displays the levels of return signals from
reflecting surfaces (most likely, metal).
The greater the response of a certain type, the more LEDs will light up in the corresponding
INPUT LEVEL gauge bar.
Recommendations
With an NLJD one typically probes
• enclosing structures (walls, ceilings, floors)
• different parts of the interior
• various objects that are not supposed to contain semiconductor material
