Atec Narda-8700-8741d-8754D-8760D-8761D - Manual (Page 2)

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Electric and Magnetic Field Measurement
RF Radiation
Safety Products
Power
Meters/Monitors
Wireless
Products
Electromechanical
RF Switches
Passive
Components
Active
Components
SHAPED FREQUENCY RESPONSE PROBES
The goal in designing and manufacturing a traditional,
“flat” frequency response probe is to make the probe
equally responsive to energy at every frequency within its
rated frequency range. In contrast, Narda’s patented
shaped frequency response probes are designed and
manufactured so that their sensitivity mirrors a particular
standard as closely as possible. For example, many of
the major standards in the world set limits for maximum
exposure at the lowest frequencies to 100 mW/cm 2 .
These same standards typically limit exposure in the VHF
region to 1 mW/cm 2 and to 5-10 mW/cm 2 in the micro-
wave region. A shaped frequency response probe de-
signed for such a standard is 100 times more sensitive in
the VHF region than at the lowest frequencies. The result
is that energy from all sources within the probe’s rated fre-
quency range are not only summed in terms of RMS
power but are also weighted in direct proportion to a par-
ticular standard.
The readout on the meter is shown in terms of Percent of
Standard. The full scale of Narda’s shaped probes is typi-
cally either 300% or 600% of a standard. This permits mea-
surements of exposure environments where the weighted
field strengths range from as high as three to six times the
maximum permissible exposure1 (MPE) level to environ-
ments where the levels are less than one percent of the
MPE. For a more complete description of how shaped
probes are used in complex, multi-signal environments,
refer to the application note Measuring RF Levels at
Multi-Signal Sites that begins on page 609.
1 Maximum Persmissible Exposure (MPE) level is only one of several
terms used to designate the limits imposed by various standards.
Other common terms are: Threshold Limit Value (TLV), Permissible
Exposure Level (PEL), action limit, and reference level.
SELECTING A SHAPED PROBE
1. Determine the standard that you will be using.
2. Determine which tier of the standard will be
used, i.e., Occupational Environment or
General Population Environment.
3. Determine whether you must measure the
magnetic field as well as the electric field.
4. Select a probe model from the table on the
next page.
ENVIRONMENTAL SPECIFICATIONS
Temperature
Operating -10°C to +55°C
Non-Operating -40°C to +75°C
Humidity 0% to 95%, non-condensing
OUTLINE DRAWINGS
1
2
3
4
5
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