Instruction manual

attached, power is supplied from the Gate through the Electronics Connector
on the rear panel. If used without a Gate, power may be supplied with either two
C-cell alkaline batteries in the Battery Holder on the rear panel or, on newer
units, from any 6 to 40 volt dc supply or NMT Power Supply connected to the
Power Connector on the rear panel.
Please see Turning on Power, in Part 4 regarding units with gates.
To the right of the power switch are two LED (light emitting diode) displays. The
lower display is formed by a horizontal row of 18 red LEDs. The first LED is a
power-on indicator; as long as there is power this first LED will be on. The next
14 LEDs are a tag signal display, depicting the size of the magnetic disturbance
being detected in the tunnel. The light moves to the right as the signal increases.
When it reaches the center of the display, marked Tag Threshol”, the detector
recognizes the presence of a tag. At and above "Tag Threshold," a solid bar of
LEDs appears to the right. The number of lit LEDs to the right of “Tag Threshold”
indicates signal strength. The last three of the 18 LEDs indicate: 1) an Error in
conveyor belt timing, 2) Low Batteries, low voltage, and 3) Dead Batteries.
The upper round LED display consists of one red LED that illuminates when a
detected tag (or excess noise) causes the signal strength to pass the Tag
Threshold.
The Low Batteries light functions similarly in units with either a Battery Holder
or with a Power Connector. In the first case, it indicates that the two C-cell
batteries are low (1.1 volts or less each) and should be replaced. It will also
indicate when either a 6 volt or 12 volt lead acid battery connected directly to the
detector (not the gate) is in need of recharging. The Detector will still function for
a short while (up to 10 hours) after this light turns on. The Dead Batteries light
indicates that the batteries are so low that the Detector will probably not function
correctly.
When the Detector, without a gate, is first turned on, the LED bar graph to the
right of “Tag Threshold” displays the battery condition. A single light indicates a
nearly exhausted alkaline battery giving no more than 0.9 volts per cell. The bar
grows to the right with increasing battery condition up to the 1.5 volts per cell of a
fresh alkaline battery. Two alkaline C- cells are good for about 60 hours of
normal operation. The detector may operate from other types of C- cell batteries,
but they are not recommended and may not properly trigger the low battery
indicator lights.
The LED bar graph to the right of “Tag Threshold” also indicates the charge
R-Series Instruction Manual 8