Rutus Alter71, User Manual

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After pressing the button the « Sensitivity » message will appear on the display,
a number describing the Sensitivity level and a linear scale showing the adjustment range. The
adjustment is done using the buttons. Pushing the button a second time will show
the Discrimination level. Adjusting the Discrimination is done in the same way as adjusting the
Sensitivity
.
Another press of the button will lead to the Notch function. The Notch point, which
we want to lock (or unlock) is chosen using the buttons. The chosen Notch point is
locked (Reject) or unlocked (Accept) using the
buttons. To quickly block or unblock
a larger range of points, the user can use the buttons: or and or
simultaneously.
After pressing the button the screen returns to the operation mode screen.
Sensitivity in the Alter71 detector may be adjusted across 90 levels. The Sensitivity level
set by the user determines the detector's range and more importantly it's stable operation. In
areas which are littered, freshly ploughed or have heavy electromagnetic interference, operating
with maximum Sensitivity is not possible. Sensitivity has to be adjusted in accordance to the
terrain where the search is being conducted and using your own experience. New users should
begin their searches with the detector set to Sensitivity levels between 40 and 60.
Discrimination is a function which enables the removal of sound signals from unwanted
objects, which have a identification number lower than the set Discrimination value.
E.g. a Discrimination value set to 20 [-30] will result in a lack of the detector’s reaction to most
small steel objects. The Discrimination value can be set within the range 0 to 120 [-90 +90].
The detector has 120 points of Notch function. Each of which can be locked individually.
This function is used to eliminate signals from objects with a specific identification point, which
helps to search in places where there is a large amount of similar, unwanted objects. For
example, to eliminate signals from spent cartridges littering a battlefield but not eliminating
signals from other objects. To make best use of this function, block readings from the unwanted
object's value, and a few points above and below this. The size of this range should be adjusted
based on the search conditions. In places where identification readouts are stable, the range of
the blocked signals should be as narrow as possible.
When using Notch it is important to remember that other objects with characteristics
similar to the „unwanted” ones will also be eliminated. For best results, only use this function in
exceptional circumstances.
If the detector is working in the 1 –120 ID range, then one ID point equals one point of
Notch discrimination. In the case of the -90 to +90 ID range, calculate Notch Discrimination
values as follows. For negative values (-90 to 0), three identification points equals one point of
Notch discrimination. E.g. -90 to -88 = 1, -87 to -85 = 2, -84 to -82 = 3 etc, and -5 to -3 = 29, -2
to 0 = 30. For positive values (0 to +90) one identification point equals one point of Notch
discrimination. E.g. +1 = 31, +2 = 32, +3 =33 etc, and 88 = 118, 89 = 119, 90 = 120.
RUTUS
Alter71
ver. 2.0 9