Revision 4.7
This manual will be continuously updated, improved and
expanded. You will find the current version at your local
distributors homepage or at www.gigahertz-solutions.de
Please carefully review the manual before using the device. It
contains important advice for use, safety and maintenance of
the device. In addition it provides the background information
necessary to make reliable measurements.
With the HF analyzers, GIGAHERTZ SOLUTIONS
Professional measurement engineering is
offered with a unique price/performance ratio
- the only one of its kind worldwide. This was
made possible through the consistent use of
innovative integrated components, as well as
highly sophisticated production engineering.
Some features have patents pending.
The HF analyzer you purchased allows a
competent assessment of HF exposures between 2.4 and 6 GHz, a range containing
Bluetooth / WLAN, WIMAX, some beam radio
and Radar frequencies. Lower frequencies
(like e.g. cellular phone frequencies, TV,
DECT) are suppressed, which means they
are not audible in the Audio Frequency
Analysis. This is to avoid falsification of the
reading.
We appreciate the confidence you have
shown in purchasing this instrument. With
the confidence that your expectations will be
met, we wish you great success in collecting
valuable information with this HF analyzer.
If you should encounter any problems,
please contact us immediately. We are here
to help. For your local partner please check:
www.gigahertz-solutions.com
Alternatively you can always turn directly:
GIGAHERTZ SOLUTIONS GmbH, Germany
D-90579 Langenzenn, Am Galgenberg 12
www.gigahertz-solutions.com
Introduction to Properties and
Measurement of HF Radiation 4
Step-by-Step-Instruction
to HF-Measurement 5
Limiting values, recommendations
and precautions 8
Audio Frequency Analysis 9
Permanently low display values? 10
Further Analysis / Opt. Accessories 11
Power Supply 11
Remediation and Shielding 11
Warranty 12
Conversion tables 13
Safety Instructions:
It is imperative to carefully study the instruction manual prior
to using the HF analyzer. Important information regarding
safety, use and maintenance is provided herein.
The HF analyzer should never come into contact with water or
be used outdoors during rain. Clean the case only from the
outside, using a slightly moist cloth. Do not use cleaners or
sprays.
Prior to cleaning the HF analyzer or opening the case, shut it
off and unplug all extension cords. There are no userserviceable parts inside the instrument.
Due to the high sensitivity level, the electronics of the HF
analyzer are very sensitive to heat, impact as well as touch.
Therefore do not leave the instrument in the hot sun, on a
heating element or in other damaging environments. Do not let
it drop or try to manipulate its electronics inside when the
case is open.
This HF analyzer should only be used for the purposes described in this manual and only in combination with supplied
or recommended accessories.
1) Volume control for the audio analysis.
Active, when switch “Mode” is set to the
position “
”
Contents of the package
Instrument
Attachable antenna
Alkaline Manganese (AlMn) 9 V battery
2) Selector switch for signal evaluation.
(inside the meter )
Standard setting: “Peak”.
Comprehensive instruction manual
3) The measurement range selected is indicated by a small horizontal bar, the units
are µW/m².
4) Connecting socket for the antenna.
5) Measurement range selector switch
1999 µW/m² (“coarse”)
199.9 µW/m² (“fine”)
6) ON/OFF switch. In middle switch-
position . . .., the audio analysis mode
is activated. In upper position
ting, you can additionally hear a signal
proportional to the field strength
. set-
1
. This in-
strument has an “Auto-Power-Off func-
2
tion“
.
7) Signal fraction
3
: The switch-position
“Full” shows the total power flux density
of all signals in the respective frequency
range, the switch position “Pulse” only
shows the amplitude modulated (pulsed)
part.
Caution: Pre-amplifiers only to be used
in the switch position “Pulse”
The original printwork on the housing is in English, of course.
The HF component of the testing instrument is shielded against interference by
an internal metal box at the antenna input
(shielding factor ca. 35 – 40 dB)
For this feature the volume control should be turned
down completely because otherwise the sound mixes
with the “audio analysis”. Similar to Geiger counter.
Typical default settings are marked yellow.
Check the HF analyzer and its antenna by
following the instructions under
“Getting Started.“
2
The instrument switches off after about 30 minutes to
avoid unintentional discharge of the battery. If the
charge condition of the battery is too low, which is
indicated by “LOW BATT” on the display, the device
will switch off after only few minutes to avoid total
discharge.
3
Implemented as new feature from November 2007
Page 3
Digital High Frequency Analyser HF W 35C
Getting Started
Connecting the Antenna
Screw the angle SMA-connector of the antenna connection into the uppermost right
socket of the HF analyzer. It is sufficient to
tighten the connection with the tightening
aid. Do not use a wrench or other tools because over tightening may damage the
threads.
The radiation in the frequency rang of this
instrument are normally vertically polarized.
An orientation of the antenna suitable for this
is as shown in the following picture:
For horizontal orientation of the antenna you
should rotate the instrument rather than
twisting the cable. The LED at the front of the
antenna indicates a good connection, which
is essential for an accurate measurement!
Do not touch the cable while measuring.
Remarks concerning the antenna
The SMA connector of the antenna to the
instrument of the highest industrial quality
available. Also the “semi rigid” cable has the
best technical parameters in the instrument’s
frequency range. It is designed for several
hundred changes of orientation without ef-
Do not twist the antenna cable
or bend it sharply!
fects for the accuracy of the measurement.
For the special design of the second connecting cable we have a patent pending. The
objective is to reduce an inherent weakness
of “simple-log.per” antenna designs made of
PCB material. For radiation incoming at an
angle to the main direction normal designs
pick up signals also below the design frequency range, which can falsify the measurement. This antenna suppresses this by 15
to 20 dB in addition to the approx. 40 dB of
the high pass filter.
Checking Battery Status
When the “LOW BATT“ indicator appears in
the center of the display, measurement values are not reliable anymore. In this case the
battery needs to be changed.
If there is nothing displayed at all upon
switching the analyzer on, check the connections of the battery. If that does not help try a
new battery.
Remember that rechargeable batteries only
have about a quarter of the capacity of the
recommended AlMn-batteries.
Note
Each time you make a new selection (e.g.
switch to another measurement range) the
display will systematically overreact for a
moment and show higher values that droop
down within a couple of seconds.
For in-depth information on the subject of
“Electro Smog” from high frequency radiation
refer to the extensive literature. This instruction manual focuses on those properties that
are particularly relevant for measurements in
residential settings.
Across the specified frequency range (and
beyond), HF radiation causes the following
effects in materials exposed to it:
1. Partial Permeation
2. Partial Reflection
3. Partial Absorption.
free field conditions one can. It is measured as
power density in mW/m
2
or µW/m².
Polarization
When HF radiation is emitted, it is sent off
with a “polarization“. In short, the electric
component of an electromagnetic wave
propagates either vertically or horizontally.
Cellular phone technology, which is of greatest interest to us, is usually vertically polarized. In urban areas, however, it sometimes
is already so highly deflected that it runs almost horizontally or at a ±45-degree angle.
Due to reflection effects and the many ways
in which a cellular handset can be held, we
The proportions of the various effects depend, in particular, on the exposed material,
its thickness and the frequency of the HF
radiation. Wood, drywall, roofs and windows,
also observe other polarization patterns.
Therefore it is always strongly recommended
to measure both polarization planes, which is
defined by the orientation of the antenna.
for example, are usually rather transparent
spots in a house.
A continuously updated most extensive collection
of exact shielding property data of construction
materials by Dr. Moldan/Prof. Pauli is available
under www.drmoldan.de
in English).
(the file is also available
Fluctuations with Regards to Space and
Time
Amplification or cancellation effects can occur in certain spots, especially within houses.
This is due to reflection and is dependent on
the frequencies involved. Most transmitters
or cellular handsets emit different amounts of
Minimum Distance
In order to measure the quantity of HF radiation in the common unit “power density“
energy during a given day or over longer periods of time, because reception conditions
and network usage change constantly.
(W/m²), a certain distance has to be kept
from the HF source. It is important to keep a
minimum distance of one to two meters between the HF35C and the source of radiation.
Background: Close to the source the electrical
and the magnetic field have to be measured
separately; one cannot calculate the one from the
All the above-mentioned factors affect the
measurement technology and especially the
procedure for testing. This is why in most
cases several testing sessions are necessary.
…and Consequences for Measuring HF Radiation
When testing for HF exposure levels in an
apartment, home or property, it is always
recommended to record individual measurements on a data sheet. Later this will allow
you to get a better idea of the complete
situation.
It is important to repeat measurements several times: First, choose different daytimes and weekdays in order not to miss any
of the fluctuations, which sometimes can be
quite substantial. Second, once in a while,
measurements should also be repeated over
longer periods of time, since a situation can
literally change “overnight.“
Furthermore you should be aware that taking
measurements indoors adds another dimension of testing uncertainties to the specified
accuracy of the used HF analyzer due to the
narrowness of indoor spaces. According to
the “theory“ quantitatively accurate HF
measurements are basically only reproducible under so-called “free field conditions”,
yet we have to measure HF inside buildings
because this is the place where we wish to
know exposure levels. In order to keep system-immanent measurement uncertainties as
low as possible, it is imperative to carefully
follow the measurement instructions.
As mentioned earlier in the introduction, only
slight changes in the positioning of the HF
analyzer can lead to rather substantial fluctuations in measurement values. (This effect
is even more prevalent in the ELF range.) It is
suggested that exposure assessments are
based on the maximum value within a locally defined area even though this particu-
Page 5
Digital High Frequency Analyser HF W 35C
lar value might not exactly coincide with a
particular point of interest in, for example, the
head area of the bed.
The above suggestion is based on the fact
that slightest changes within the environment
can cause rather major changes in the power
density of a locally defined area. The person
who performs the HF testing, for example,
affects the exact point of the maximum
value. It is quite possible to have two different readings within 24 hours at exactly the
same spot. The maximum value across a
locally defined area, usually changes only if
the HF sources change, which is why the
latter value is much more representative of
the assessment of HF exposure.
The potential shifting of local maxima needs
special consideration when setting up WLAN
networks.
The following guidelines are meant for measuring immissions in buildings, i.e. power density values for comparison with recommended allowables.
A second application of this instrument is to
locate the source and strength of a specific
radiation (emission). The log.per antenna
coming with this instrument is best suited for
this. For defining counter measures and
shielding see separate section at the end of
this chapter.
Step-by-Step-Instruction to HFMeasurement
Preliminary Notes Concerning the Antenna
Logarithmic-periodical antenna designs can
be optimized for two purposes:
• Direction finding (narrow opening angle sensitivity at the expense of
measurement accuracy)
• Quantitative measurements (wide angle sensitivity at the expense of direction finding.
Our antenna strikes a good compromise between the two, with very good accuracy with
still good direction finding. The direction to
the source can be determined with good accuracy, a prerequisite for remedial action.
The readings from the instrument’s display
reflect the integral power density in the “antenna lobe”. (ie., the antenna is most sensitive, with a rounded peak, to radiation from a
direction parallel to its axis with the sensitivity tapering off rapidly with increasing angle
of incidence.)
The logarithmic-periodic antenna supplied is
optimized for the range 2.4 to 6 GHz 2400 to
6000 MHz).Its characteristic is compensated
by circuitry within the instrument over the full
range specified. This covers the following
services (some only in Europe /Germany
Oct. 2006
):
as of
2412 - 2484 MHz WLAN b/g / Bluetooth
2450 MHz Microwave oven
2700 - 2900 MHz Airport Radar
2920 - 3100 MHz Nautical Radar
3410 - 3494 MHz WiMAX Low band
3510 - 3594 MHz WiMAX High band
3600 - 4200 MHz Beam radio
4200 - 4400 MHz Aviation Radar (height)
5030 - 5091 MHz MLS
5150 - 5350 MHz Wlan a/h BAND I
5470 - 5725 MHz Wlan a/h Band II
5725 - 5875 MHz WLAN
All of these are digitally pulsed and for this
reason considered of special biological relevance by concerned physicians.
For monitoring of these critical sources of
radiation as conveniently as possible the frequency band of the LogPer aerial supplied
together with the instrument has been limited
intentionally by its design to frequencies
above 2.4 GHz, i.e. frequencies below 2400
MHz are suppressed by the antenna design.
The suppression is additionally enforced by
an internal highpass filter at 2.4 GHz. This
reduces the disturbing impact of sources like
radio broadcasting, television stations, amateur radio, cellular and DECT phones on the
measurements to a minimum.
Beyond 6 GHz the sensitivity curve of antenna and instrument droop slowly. To make
use of this fading sensitivity no lowpass filter
has been built in.
In order to measure frequencies below 2.4
GHz Gigahertz Solutions offers a wide range
of instruments.
This is helpful to gain insight into the overall
situation. Since the actual number values are
of secondary interest in this phase, it is usually best to simply follow the audio signals
which are proportional to the field strength.
Procedure for the
Quick Overview Measurement:
The HF analyzer and antenna should be
checked following the instructions under
“Getting Started.“
stantly moving the antenna or the HF analyzer with attached antenna, in each direction. This will provide you with a quick overview of the situation. In in-door spaces, antenna movements towards the ceiling or the
floor will reveal astonishing results.
As already mentioned above, overview
measurements are not meant to provide
accurate results, but to identify those
zones within which local maximum values
are found.
First set the measurement range (“Range
Selection”) switch to “1999 µW/m²” (coarse).
In this phase measurements beyond the
range of the display do not matter, as the
Quantitative Measurement
Settings
loudness of the monitoring tone is still proportional up to beyond 6000
µW/m². Only if
the displayed measurement values are persistently below approx. 10
the measurement range “199.9
µW/m², change to
µW/m²” (fine).
Note: When switching from the range
“1999
µW/m²” to “199.9µW/m²”, the volume
of the audio signal increases sharply.
Set the “Signal Evaluation” switch to “Peak”
HF radiation exposure can differ at each
point and from all directions. Even though the
HF field strength of a given space changes
far more rapidly than at lower frequencies, it
is neither feasible nor necessary to measure
all directions at any given point.
Since there is no need to look at the display
during an overview measurement, you only
need to listen to the audio signal. It is very
easy to walk slowly through in-door or outdoor spaces in question. In doing so con-
After having identified the measurement
points subject to closer investigation following the instructions in the previous section,
quantitative precise measurements can be
started.
Setting:
Measurement Range Selection
Select the appropriate switch settings as
described under “Quick Overview Measurements“. Basic rule for measurement range
selection:
- As coarse as necessary, as fine as possible.
Note:
Power densities beyond the designed range
of the instrument (display shows “1” on its
left side with the range set on “1999 µW/m²”)
can still be measured by inserting the attenu-
ator DG20_G6, available as an optional accessory. When using this attenuator, multiply
the displayed power flux density by 100 to
calculate the actual measurement. If more
sensitivity is needed then use the preamplifier use the pre-amplifier
HV20_2400G10 and divide the reading by
100.
Setting:
Signal Evaluation
Signal Evaluation – Average / Peak
A pulsed signal consists of sections of its
time period with high output and another
sections with zero output. Their maximum
output is the wave peak. The following illustration shows the difference in the evaluation
of a pulsed signal if displayed as an average
value reading or a peak value reading.
peak value: 10
avg. value: 1
HF-energy in µW/qm
e.g. 1 pulse every 10 µS
Note: The peak HF radiation value, not the
average value, is regarded as the measurement of critical “biological effects“. The peak
value is displayed in the switch setting:
“Peak”. The average value is displayed in the
switch setting: “Average”. It will show
1µW/m² (=(1*10)+9*0))/10).
The reading obtained with the setting “peak”
with the Gigahertz instrument is often termed
Page 7
Digital High Frequency Analyser HF W 35C
descriptively by building biologists as “average of the peak”, thus meeting the requirements. “Official” allowables are based on
consideration of averages. For assessing of
”official” measurements such comparisons
are useful.
Note for users of professional spectrum analyzers:
• For pulsed radiation Gigahertz’ HFanalyzers in switch setting “Peak” show
the same value on the display as obtained by the “Max Peak” or “Positive
Peak” Detector of a modern spectrum
analyzer (calculated into µW/m²).
• The setting “average” corresponds to the
setting “RMS-detector” of modern spectrum analyzers.
Quantitative Measurement:
Determination of Total High Frequency
Pollution
As described in Getting Started, attach the
LogPer antenna to the HF analyzer. Hold
the HF analyzer with a slightly outstretched arm because objects (mass) directly behind
it “like yourself”, have effects on the testing
result. Your hand should not get too close to
the antenna, but should be near the bottom
end of the instrument.
In the area of a local maximum, the positioning of the HF analyzer should be changed
until the power density (the most important
measurement value) can be located. This can
be achieved as follows:
- When scanning “all directions“ with the
LogPer to locate the direction from which
the major HF emission(s) originate, move
your wrist right and left. For emission
sources behind your back, you have to
turn around and place your body behind
the HF analyzer.
In building biology, it is well accepted that
exposure limit comparisons should be
based on the maximum value emitted
from the direction of the strongest
radiation source.
Quantitative Measurement:
Special Case: Radar
For air and sea navigation a radar antenna
slowly rotates around its own axis, thereby
emitting a tightly bundled “radar ray“. Even
with sufficient signal strength, this ray can
only be detected every couple of seconds,
for a few milliseconds. This requires special
measurement technology.
Please use the following procedure to ensure
correct readings:
Setting: “Signal Evaluation” – “Peak”. With
the help of the audio analysis (a very short
“Beep” every couple of seconds), one can
clearly identify a radar signal. With this setting and the LogPer antenna you can identify
the direction of the source of the signal.
- Through rotating the HF analyzer, with at-
tached LogPer antenna, around its longitudinal axis, determine the polarization
plane of the HF radiation.
- Change the measurement position and
avoid measuring exclusively in one spot..
because that spot may have local or antenna-specific cancellation effects.
Some manufacturers of field meters propagate the idea that the power density should
be obtained by taking measurements of all
three axes and calculating the result. Most
manufacturers of professional testing equipment, however, do not share this view.
The long delays between pulses may consume a great deal of time trying to detect
signal direction with a LogPer aerial.
If you have identified the direction of highest
radiation peaks, then keep holding the instrument into that direction and take a note
of the highest reading you get as a basis for
the evaluation of the radiation.
Depending on the type of radar, the average
level can be up to 10 dB or 10 times lower
than the actual peak power density, sometimes even more. To be on the safe side one
should multiply the radar peaks (i.e. peak
minus background radiation between pulses)
Page 8
Digital High Frequency Analyser HF W 35C
by ten and compare this value with limits or
recommendations.
Please note that there are Radar systems
that are operated at even higher frequencies
that can be measured with this instrument,
yet possibly not the full intensity.
Quantitative Measurement:
Identify where the radiation enters a structure
As a first step eliminate sources from within
the same room (e.g. cordless phones, wireless routers, etc.) Once this is completed, the
remaining radiation will originate from outside. For remedial shielding it is important to
identify those areas of all walls (including
doors, windows and window frames!), ceiling
and floor, which are penetrated by the radiation. To do this one should not
stand in the
centre of the room, measuring in all directions from there, but monitor the permeable
areas with the antenna (log.-per.) directed
and positioned close to the wall
2
. That is because the antenna lobe widens with increasing frequency. In addition reflections and
cancellations inside rooms make it difficult
and often impossible to locate the “leaks”
accurately. See the illustrating sketch below!
antenna
wall
potentially HF-permeable
part of the wall
wrong!
right!
The uncertainty of localization with HF- antennas
antenna
wall
potentielldurchlässigerBereich
The shielding itself should be defined and
surveyed by a specialist and in any case the
area covered by it should be much larger
than the area of incidence.
Limiting values, recommendations and precautions
Precautionary recommendation
for sleeping areas with pulsed radiation
Below 0.1 µW/m²
(“no anomaly” according to recommenda-
tions to the standard of building biology
measuring technology SBM 2003)
for indoor areas
below 1 µW/m²
(according to: Landessanitätsdirektion
Salzburg, Austria)
The official regulations in many countries
specify limits far beyond the recommendations of environmentally oriented, critical
doctors, “building biologists” and many scientific institutions and also those of other
countries. They are vehemently criticised, but
they are nonetheless “official”. The limits depend on frequencies and in the HF range of
interest here they are at 10 W/m² for the frequencies considered here, far beyond 10
million times the recommendations. Official
limits are determined by the potential heat
2
Please note: In this position the readings on the LCD
only indicate relative highs and lows that cannot be
interpreted in absolute terms.
generation in the human body and consequently measurements of averages rather
than peaks. This ignores the state of envi-
ronmental medicine. The “official” limits are
far beyond the range of this instrument,
which is optimized for accurate measurement
of power densities targeted by the building
biologists.
The standard SBM 2003 cited above classifies power densities of below 1 µW/m² as “no
anomaly” for non pulsed radiation in sleeping
areas, and for pulsed radiation one tenth of
that.
The cerebric pulsing found in the Alpha frequency range (about 10 Hertz), as for instance used by WLAN, are considered especially active. Effects on human health have
already been observed at values far below
0.1 µW/m²!
The "Bund für Umwelt und Naturschutz
Deutschland e. V." (BUND) proposes 100
µW/m² outside buildings. In view of the
shielding properties of normal building materials, far lower values exist inside buildings.
In February 2002 the Medical Authority of the
Federal State Salzburg, Austria, recommends
to reduce its “Salzburger Precautionary Recommendation” from 1 000 µW/m² to 1 µW/m²
inside buildings and 10 µW/m² outside.
These limits are based on empirical evidence
over the past few years.
The ECOLOG-Institute in Hannover, Germany made a recommendation only for outside areas, namely 10000 µW/m². This is well
above the recommendation by building biologists and aims at getting consent also
from the industry. This would possibly enable
a compromise for a more realistic limit than
the government regulations cited above. The
authors qualify their recommendation in
Page 9
Digital High Frequency Analyser HF W 35C
- The limit should be applicable to the maxi-
mum possible emission of the transmitting
stations. As the emission measured depends on the constantly varying actual
load, this restricts the normal exposure
much further.
- A single station should not contribute more
than one third to this total.
- The extensive experience and findings of
medical and building biology specialists
could not be considered for the proposed
limits, as their results are not sufficiently
documented. The authors state, that “scientific scrutiny of their recommendations is
needed urgently”.
- Not all effects on and in cells found in their
research could be considered for the proposed limits, as their damaging potential
could not be established with sufficient certainty.
In summary it confirms the justification of
precautionary limits well below the present legal limits.
Many different frequencies within the frequency band between 2.4 and 6 GHz, are
being used by many different services. The
audio analysis of the modulated portion of
the HF signal, help to identify the source of a given HF radiation signal.
How to proceed:
Set the On/OFF switch at
For audio analysis, simply turn the volume
knob of the speaker at the top of the case all
the way to the left (“-“). If you are switching
to audio analysis while high field strength
levels prevail, high volumes can be generated
quite suddenly. The knob is not fastened with
glue to prevent over winding. However, if by
accident you should turn the knob too far,
simply turn it back again. No damage will be
caused.
Sounds and signals are very difficult to describe in writing. The best way to learn the
signals is to approach known HF sources
very closely and listen to their specific signal
patterns. Without detailed knowledge, the
characteristic signal patterns of the following HF sources can be easily identified: 2.4GHz telephones (base station and handset)
as well as cellular phones, the signal patterns
of which can be divided into “a live connected phone call“, “stand-by mode“ and
especially the “establishing of a connection“.
The typical signal patterns of a cellular phone
base station can also be identified this way.
For comparison reasons you are well advised
to take measurements during high-traffic
times, as well as some times during the
night, in order to familiarize yourself with the
different noises.
.
The volume can be controlled with the “volume” (speaker) knob. Note: The power consumption of the speaker is directly proportional to the volume.
On our home page (www.gigahertzsolutions.de) there is a link to some typical
samples of audio analyses as MP3-files.
Marking of un
Un-pulsed signals (more precisely: not amplitude-modulated signals) by their very nature
are not
therefore easily missed. For that reason they
are marked by a uniform “rattling” tone, with
its volume proportional to its contents of the
total signal. This “marking” has a frequency
of 16 Hz, and an audio sample can also be
downloaded as a MP3 file from our website.
If pre-amplifiers are applied with this device,
the setting of the signal switch must be
“Pulse”, as the “marking” feature will “interpret” the white noise as an unpulsed signal
and thus be heard all the time. All relevant
field sources in this range are pulsed anyway
so there is no problem related to switch to
“Pulse”.
audible in the audio analysis and
pulsed signals
Page 10
Digital High Frequency Analyser HF W 35C
Permanently low display values?
Fortunately, exposures in the frequency
range of the HFW35C are not yet widespread. Therefore, we have often been asked
whether the device does in fact work, as it
rarely ever shows any values. In the following
please find answers to frequently asked
questions:
“The HFW35C only indicates very low
measuring values”
Answer:
Naturally, the radar and directional radio frequencies within the frequency range of the
HFW35C will only be found regionally. At
present, the components for the upper
WLAN band (from 5 to 6 GHz) are still difficult
to obtain, so you will only encounter selective
exposures in this frequency range. The WiMAX network (from 3 to 5 GHz) is only active
in some testing locations, its extension all
over the country is, however, expected to be
accomplished within the coming two years.
Therefore, for the time being, the HFW35C
can be considered as a device enabling to
exclude potential stronger exposures caused
by these sources at the respective site. This
already is an important information.
The presently most frequently measured appliances are Bluetooth appliances found at
the lowest end of the involved frequency
range… Questions related to this field:
“Even when transmitting data with my
notebook, only low values are shown on
the display”
Thanks to the integrated transmitting power
control, the notebook won’t draw more
power than needed for its communication
with the remote station. However, if you
measure within splitting distance to a notebook just transmitting data wireless, you will
obtain values, at least in the finer measuring
range.
“No measurement values obtained, even
directly next to my WLAN/Bluetoothcompatible notebook…”
“…although the display indicates: ‘searching wireless connections’”
Answer:
While searching a network, the notebook is
basically not transmitting itself, so obviously
no measurements can be obtained.
“…although my notebook shows various
networks with good reception”
Answer:
A notebook has no problems with the reception, even if the signal strength is a factor
1000 or more below the lowest display value
of the measuring device or below the building biology recommendations.
“In the finer measuring range, the HFW
never shows values beyond 0.3 to 0.5
µW/m² (with or without antenna)”
Answer:
This is the residual noise of the device. It
would be easy to wire the display in such a
way that it would approach zero as soon as
only little values are shown, thus suggesting
higher precision (paradoxically, the producer
himself even recommends to do so!). However, we do not consider this useful, and pre-
fer to indicate the residual noise the way it is.
Yet, if measurements without antenna reach
values beyond 0.9 µW/m² within the fine
measurement range (or 9 within the coarse
measurement range), you should return the
device for investigation, as this does no
longer correspond to the specifications.
Simple testing method:
Take measurements only few meters away
from an active point of access (e.g. “DSLWLAN-router). Its “heartbeat”, the well
known “tac-tac-tac…”, will be clearly audible, and the corresponding pulsed radiation
measurable. If this works out, errors can be
(almost) excluded, even for the highest frequency range. At least we have not yet had a
frequency selected defect of this kind in all
the years of producing HF devices.
THE solution: a pre-amplifier!
Based on the statements in the chapter “Limiting values, recommendations and precautions” about the extreme effects of WLAN
signals on the human biology, an increased
range appears to make sense. There is a preamplifier available for the amplification by a
factor of 100 (HV20_2400G10). Please note:
Always measure in the “Pulse”-mode
when applying the pre-amplilfier.
Page 11
Digital High Frequency Analyser HF W 35C
Further Analysis /
Optional Accessories:
An auxiliary attenuator to increase or decrease the range of power densities which
can be processed with this instrument is under development, and two pre-amplifiers for
the amplification by a factor of 100 and 1000
are already available (please see above).
Instrument for lower frequencies
For measurement of signal frequencies
above 27 MHz (including: CB radioing, analogue and digital TV and radio TETRA etc.)
we offer the instruments eHFE35C and
eHFE59B.
Instrument for yet higher frequencies
An instrument up to 10/12 GHz is under development for 2007.
Available for low frequencies:
Electro smog is not limited to the Radio Frequency range!
Power Supply
Changing the Battery
The battery compartment is at the back of
the analyzer. To remove the lid, press on the
grooved arrow and pull the cap off. The inserted foam will press the battery to the lid,
thus avoiding it to rattle. Therefore, when
pushing back the lid you will note a little resistance.
Auto-Power-Off
This function conserves energy and extends
the total operating time of the battery.
1. In case you have forgotten to turn OFF
the HF analyzer or it has been turned ON
accidentally during transport, it will shut
off automatically after 40 minutes of continuous use.
2. If “low batt” appears vertically between
the digits in the center of the display, the
HF analyzer will turn OFF after 3 min in
order to avoid unreliable measurements.
In that case change the battery.
Remediation and Shielding
Please call us or send us an e-mail.
We will assist you in any shielding project
you might have.
The shielding effect of the various materials
is stated normally in “dB”, e.g. “20 dB”.
Conversion of shielding effect into reduction
of power density
„10dB“ is measured value divided by 10
“15dB” is measured value divided by ~30
”20dB” is measured value divided by 100
”25dV” is measured value divided by ~300
”30dB” is measured value divided by 1000
etc.
Please be aware of the manufacturer’s notes
about the normally achievable shielding effects, as 100 % shielding is almost always
impossible. Partial shielding reduces the attenuation considerably. That is why shielding
of seemingly radiation tight adjacent areas is
highly recommended.
Also for the low frequency range such as
power (distribution and domestic installations) including their higher harmonics we
offer a broad range of affordably priced instruments with high professional standards.
If you are interested please do not hesitate to
contact us. Contact details can be found at
the end of this brochure.
Most recommended building biology values for HF
radiation are given in W/m², which is why this instrument is displaying in power density, µW/m² resp.
mW/m². A display in dBm as e.g. on a spectrum analyzer requires transformation by a complicated formula,
which depends on frequency and specifics of the antenna used. A “re
sense.
Mejor apantallamiento respecto a influencias terrestres, ondulación reducida
Antena compensada (HFW: filtro de pase alto a 2,4 GHz integrado)
Antena de sondeo LAT10 con característica direccional muy ajustada hasta 1,9 GHzopc.opc.opc.opc.opc.opc.opc.opc.
UBB27_G3: Antena de banda ultra ancha quasi-isotrópica de 27 MHz a 3,3 GHz
Indicador digital: en µW/m²
Análisis acústico
Señal acústica proporcional a intensidad de campo (Piezo)
Señal acústica con diferenciado de frecuencias para facilitar el diagnóstico de radiaciones (altavoz de
membrana de 40mm)
Regulador de volumen para altavoz o cascos
(2,5 - 3,3 GHz con mayores tolerancias)
(1)
(1)
(Interconector para medir valores 100 veces mas intensos)
(como DG20 con linealidad de frecuencia mejorada y pase DC)
(Interconector para medir valores 10 veces mas debiles)
(Interconector para medir radiaciones 100 veces inferiores)
Medición sencillaMedición profesional
Valores aconsejados en cama
("idóneos") según SBM´08:
0,1 µW/m²
opc.opc.opc.
(incl. Antena, con UBB27 tolerancia aumentada por debajo de 100MHz)+/-6dB +/-6dB +/-6dB +/-6dB+/-6dB+/-4,5dB +/-4,5dB+/-3dB+/-3dB+/-3dB
(no log-per.)
*
opc.opc.opc.opc.
opc.opc.opc.opc.
opc.
opc.
opc.opc.opc.opc.opc.opc.
opc.
en combinación con los NFA, también es posible presentar los valores en V/m HFW59B in 2010
Page 15
Medidores AF
CEM-Ti * Medición y Blindajes CEM * 960 913 911 * cem@teleingenieria.es
Filtro de pase alto HP800_G3 para mejorar la discriminación de frecuencias por debajo de
Salidas de señal
Salida DC para archivo de datos
Salida audio (señal AC modulada) para PC (con tarjeta de sonido) / auriculares / analizador de espectro
Salida AC especial para serie NFA
(para cargar o para abastecimiento externo de tensión)
Entrada de antena con telealimentación
Vida útil con una carga de batería
fácil)
(por ej. para antena activa y filtro, amplificadores etc.)
(con uso de UBB27 la mitad)10-12h6-7h6-7h6-7h6-7h7-8h7-8h7-8h7-8h7-8h
Maletín
Maletín acolchado K1
( medidas. 27 x 18 x 8 cm )opc.opc.
Maletín acolchado K2( medidas. 33 x 27 x 16 cm ) para 2 aparatos y antena
Maletín de aluminio K3(Aluminio cepillado; medidas. 52 x 40 x 21 cm ) interior estructurable