Atec EA5091, EB5091, EC5091, ED5091 User Manual

E-FIELD PROBES

EA5091 EB5091 EC5091 ED5091

Measuring electric fields
with shaped frequency
response up to 50 GHz

using instruments in the NBM-500 family

Frequency shaping to match the ICNIRP,

FCC, IEEE or Safety Code 6 standard for
occupational/ controlled environment

Results are directly displayed in

“% of Standard“

Precise results without the need to know the

emitted frequency

Isotropic (non-directional) measurements

The probes contain 6 dipoles, three diode based and three thermo­couple based dipoles. The correctly tuned overlap of two dipoles, one
acting as a high pass filter the other as a low pass filter, provides a
frequency sensitivity that mirrors a particular standard. Testing for
compliance to that standard is very easy to perform, since you no longer
have the need to know the emitted frequency.

APPLICATIONS

Electric fields from 300 kHz to 50 GHz (3 MHz to 50 GHz with EB5091)
can be detected. The probes are particularly suitable for measuring
human safety limit values in mobile phone, telecom transmitter and
broadcasting environment.

CALIBRATION

The probes are calibrated at several frequencies. The correction values
are stored in an EPROM in the probe and are automatically taken into
account by the NBM instrument. Calibrated accuracy is thus obtained
regardless of the combination of probe and instrument.

NSTS 0807-E0239A-0.0 1 / 3 Subject to change

DESCRIPTION - Shaped 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 (or
guidance) as closely as possible.

For example, many of the major guidances and standards in the world
set E-field limits for maximum human exposure at 614 V/m (1000 W/m
at lower frequencies (~1 MHz). At frequencies of 30 to 300 MHz the
limits are typically much less, 61.4 V/m (10 W/m
(100 times the power). A shaped frequency response probe designed
for such limits is 100 times more sensitive in the 100 MHz region, than
at 1 MHz.

If you were performing a survey of a site with a flat frequency response
probe that has both of the above frequency ranges and your survey
indicated 137 V/m (or 50 W/m
site was out of compliance without turning one of the emitters off. Again,
given the example above, the site could be generating anywhere from
5% to 500% of the human exposure limit. There are many sites with
multiple emissions (rooftops, flight lines, broadcast towers) that have
emitters at different exposure limits.

If your interest is general safety measurements, to know if you comply
with an exposure limit or not, you will find shaped probes easy to use in
any environment. The display of total field strength with shaped probes
is not in terms of V/m or W/m
site, a result of 15% is simple to understand. The total detected field
strength of each emitter (to its limit, at its frequency) has added up to
15%. Besides the ease of use, the main advantage is that you no longer
have the “need to know” the frequency when using a shaped probe.

2

), it would be difficult to determine if the

2

, it is “% of Std.” So at a multiple emitter

2

), a difference of 20 dB

2

)

Table: Standards and matching probe models

Standard or Guidance Level Model

U.S. FCC, 1997 Occupational/ Controlled EA 5091

IEEE C95.1-2005 Controlled Environment EB 5091

Canada Safety Code 6, 1999 RF/Microwave Worker EC 5091

ICNIRP Rec. 1998 Occupational ED 5091

NSTS 0807-E0239A-0.0 2 / 3 Subject to change