Products Catalog

Specification

FEATURES:

The Selective Radiation Meter (SRM) is a hand-held frequency selective
measuring device designed for safety analysis of high frequency
electromagnetic fields. Broadcasting equipment operators and radio
network providers, measurement services, and authorities can use the
SRM to selectively detect individual telecommunications services and
evaluate them according to applicable standards.
The SRM comprises a basic unit plus measuring antenna. The basic
unit contains a spectrum analyzer covering the frequency range from
100 kHz up to 3 GHz. It can be combined with antennas from Narda or
from other manufacturers. Isotropic (non-directional) measurements in
the range from 75 MHz up to 3 GHz can be made using the Narda three
axis antenna, covering everything from VHF radio up to W-CDMA and
UMTS services.
The combination of basic unit plus antenna is portable, robust, battery
operated, and provides all the functions needed for evaluating, storing
and documenting the results without the need for an external PC.
Results can be uploaded to a PC for archiving.

APPLICATIONS :

The SRM was specifically designed as a hand-held measuring device
for electromagnetic field safety requirements. It is equipped with tailor
made operating modes for the preferred applications, but it can also be
used for general field strength measurements, just like an ordinary RF
spectrum analyzer. The preferred applications are:

1. Comparison measurements in known field environments.

These are often needed at so-called “shared sites�, where several
mobile phone operators share a common antenna site. The SRM
indicates the overall field strength and the contributions made by the
individual services, either as absolute values or as a percentage of the
permitted limit value. Operators, authorities, and measurement service
providers can then demonstrate on-site that immission safety limit
values are being adhered to, or they can determine which operator
needs to reduce transmission power, and by how much, in order to do
so.

2. Survey measurements in unknown field environments :

These are needed wherever a major field source cannot readily be
identified, but immission limit values still have to be adhered to, such as
at the workplace, in public or private areas, or for particularly sensitive
protected areas like kindergartens, schools and hospitals. Authorities and measurement service providers can use the SRM not only to check
whether the applicable limits are being adhered to, but also to get a
rapid overview of all the field sources in the frequency range of interest
that may be relevant to human safety.

3. Individual telecommunications service measurements Controlling field emissions is the responsibility of every service provider.
With the SRM, it is possible to selectively detect every transmission
frequency used and every occupied channel of the particular service,
even in a complex field environment and in close proximity to other
strong emitters. The results can be integrated over the frequency range
used by the service, displaying the overall result as an absolute value or
as a percentage of the applicable limit value. It is also possible to
determine the field emission that would occur if all traffic channels were
operated at full load by extrapolation from the field strength of a control
or pilot channel operated continuously at full load.