Narda 34 Nardalert S3
6 Instrument maintenance
Operational tests
Units should be visually inspected for complete and correct battery condi-
tions, switches and overall mechanical integrity. Units should pass the
“Turn-on” sequence and indicate full or nearly full battery condition.
After successful completion of operational testing, units should be
connected to a computer through the Fiber Optic port, to verify communi-
cation capability.
! All NS3 models need to be returned to their local calibration facility at
least once every 4 years for replacement of their internal clock battery.
There are no operator accessible controls or written procedures avail-
able to perform this critical step. If batteries are not changed they may
pose a safety hazard as well as damaging the NS3 itself.
Required eld response by design
0.1 to 10 MHz = Radial Only
10 to 1600 MHz = Radial and Vertical
1.6 to 100 GHz = Vertical and Horizontal
Maximum errors are as follows:
+4.5 / -3.0 dB for 100 kHz to 30 GHz
+2.5 / -6.0 dB 30 to 50 GHz
+2.5 / -6.0 dB 50 to 100 GHz, Typical
TEM cell (f < 300 MHz)
The NS3 is factory veried in a one-meter TEM cell, for frequencies
between 100 kHz to 300 MHz. Since it is responsive to the radial compo-
nent, it is positioned halfway between the septum and outer wall, in the
radial orientation (Label facing septum). The LEDs should be facing away
from the opening of the TEM cell when using remote cables to collect data,
however the unit can be positioned with the LEDs facing the front of the
TEM cell when manually verifying performance.
Generally the unit is tested at 1, 10, 50, 100, 150, 200 and 300 MHz while in
the TEM cell. Power should be increased slowly until the NS3 alarms at the
set Alarm 1 level (50%). Slowly decrease and then increase power again to
determine dB dierence from calculated to actual alarm points.
To Next Page
Loading...
Need help?
General