above initial position and 0.3 m above the floor and 1m to the left and right of the
iv. Measure and record the highest power in this volume
b. Attenuated Level at Vertical Polarization
i. Both Receive and Transmit Antennas are in Vertical Polarization
ii. In all the following measurements the Receive Antenna is held in Vertical
Polarization and kept at a distance of 0.3 m from the wall
iii. Starting with the Receive Antenna directly parallel to the Transmit Antenna begin to
slowly move the Receive Antenna in a Volume Parallel to the shielded room wall 1 m
above the initial position and 0.3 m above the floor (measure 0.3 m from the floor to
the bottom of the antenna) and 1 m to the left and right of the initial position
iv. Measure and record the highest power in this volume
3.3.7.4 Shielding Effectiveness calculation
The shielding effectiveness is calculated with the reference level measurement and the
attenuated level measurement as defined in Equation 1:
SE (db) = V
Ref_max
- V
Att_max
or
SE (db) = P
Ref_max
- P
Att_max
Where:
SE : Shielding Effectiveness in dB
V
Ref_max
, V
Att_max
: Reference measurement in dBuV
P
Ref_max
, P
Att_max
: Reference measurement in dBm
3.3.8 RF shielded Room Ground Isolation Resistance Measurement Method
WARNING
ELECTRICAL SHOCK HAZARD
THE RF SHIELDED ROOM MUST BE PROPERLY GROUNDED.
1. This section does not apply to upgrades
2. This test must be made using either an isolated, current limited, high-voltage (>150 VDC)
DC source and DMM to read drop across the limiting resistor or a Megger instrument
capable of reading values less than 1000 ohms. Conventional resistance meters employing
test sources of 9 VDC or less must not be used
3. The ground isolation resistance measurement is performed by the following procedure:
a. All power to the enclosure is removed. For safety reasons, an AC voltage measurement
will be made to verify that no power is connected
b. With electrical power and intentional ground disconnected, connect the test instrument
between the shielded enclosure and AC power ground
SIGNA Voyager Pre-Installation
Direction 5680008–1EN, Revision 2
164
3 RF Shielding Effectiveness and Ground Isolation
Testing
