RF Radiation Review: How Green is Your Cordless Phone?

Do green building practices include low EMF and RF radiation exposures? The answer is usually NO. Green building practices usually do not address EMF and RF exposure and reduction methods. We have a look at the use of DECT cordless phones indoors and the exposure pattern and the desirable elements in cordless phones.

What Does Green Mean?

The term “green” is the magic word of today and is being use ubiquitously with many products and processes for the indoor environment. But want does a “green” building actually mean and entail? Do we mean:

• Natural materials?


• Non-toxic materials?


• Sustainable materials?


• Energy efficiency?


• Recycled materials?


• Low emission materials?


• Low carbon foot print?

Most of us are familiar with indoor environmental quality. But does that also include low EMF and RF environments? This presentation will provide an insight on how a small common household item can have a major impact on our electromagnetic environment inside our buildings. We will review some low emitting or “green” devices which are available.

DECT Technology Has Finally Reached US Shores

Beginning last year, phones of the DECT 6.0 generation started flooding the US market. DECT is the abbreviation for Digital Enhanced Cordless Telecommunication technology. In the last decade, only Europeans used this technology and were confronted with its headaches.

The 2.4 GHz band has been used by the majority of cordless phones in the last five years. However, this band has become crowded with devices such as microwave ovens, wireless area networks (WLAN), Bluetooth, cordless phones and remote control devices. This has led to interference and performance issues so the manufacturers have moved to the 5.8GHz frequency band and the DECT 6.0 technology.

The problem with the DECT phones is that the base station is permanently sending (radiating), 24 hours a day, no matter if the system is in use or not. Indoor environmental consultants have rallied against their use for decades. There were so many outcries that it had an impact. Major European manufacturers now offer environmental safer versions, with sleep mode or reduced output in stand by mode.

Regulatory Standards

Regulatory maximum exposure limits are set by the FCC (Federal Communication Commission) for cellular providers and OSHA (Occupational Health and Safety Administration) for employee workplace safety. These regulatory exposure threshold limits are high and are solely based on the thermal heating effect of microwave radiation. However, many scientists and research publications have shown that other biological effects exist below the thermal threshold. The question the researchers and physicians are grappling with is if these effects have negative biological effects? Table 1 provides you with an overview of different international regulatory standards and recommended precautionary limits by different entities.

Table 1: International Regulatory Threshold Limits, References and Guidelines

Entity	Power Density
Regulatory – FCC/ANSI – USA (800-900 MHz)	579,000 nW/cm2
Regulatory – Italy, Poland, Hungary, Bulgaria	10,000 nW/cm2
Regulatory – Switzerland	4,500 nW/cm2
Recommendation – Ecolog Hannover, Germany (2003)	300 nW/cm2
Recommendation – Salzburg Resolution, Austria (2000)	100 nW/cm2
Recommendation – STOA – EU Parliament (2001)	10 nW/cm2
Average range in metropolitan areas	0.5 – 2 nW/cm2
Background levels in residential areas	0.05 -0.5 nW/cm2
Necessary for cellular phone reception	0.0001 nW/cm2

 

The BioInitiative Report

 

About a year ago, an international working group of scientists, researchers and public health policy professionals, The BioInitiative Working Group, has released its report on electromagnetic fields (EMF) and health. It raises serious concerns about the safety of existing public limits that regulate how much EMF is allowable from power lines, cell phones, and many other sources of EMF exposure in daily life.

Public health expert and co-editor of the report, Dr. David Carpenter, Director, Institute for Health and the Environment at the University of Albany, New York asserts: “This report stands as a wake-up call that long-term exposure to some kinds of EMF may cause serious health effects. Good public health planning is needed now to prevent cancers and neurological diseases linked to exposure to power lines and other sources of EMF. We need to educate people and our decision-makers that, business as usual, is unacceptable”.

The Working Group conducted a comprehensive meta analysis of existing research, and found that a significant number of studies have shown potential effects such as increased and altered cell proliferation, influences on hormones, heart, circulatory, and nervous systems. The Working Group recommends prudent avoidance of excessive EMF’s. Table 2 outlines the suggested exposure guidelines.

Table 2: BioInitiative Report Guideline Vales

Fields	Location	Value
EMF	Homes and Schools	<1 mG
EMF	Other Buildings	<2 mG
RF	Outside	<100 nW/cm²
RF	Inside	<10 nW/cm²

You can obtain a copy of the BioInitiative Report by downloading it from the following website www.bioinitiative.org .

Historic Timeline

Let’s have a brief look at the development of phone communication equipment and the current state of the industry. We started with the wired phone lines which are disappearing rapidly. This trend is very much supported by the service providers for cost and profit considerations.

Communications devise during the author’s childhood

Rotary phone with wired phone lines

 

Analog cordless phone

Digital Revolution

Digital cordless phone

Table 3 outlines the historical chronology of cordless phones, their technology, frequencies and radiation exposure effect.

Table3: Cordless Phone Technologies, Frequencies and Radiation level

Technology	Frequency	Emissions During Stand-by
Wired	DC	No
Analog	400 MHz	No
Digital	915 MHz	No
ISM Band	2.4 GHz	Yes/No
ISM Band	5.8 GHz	Yes/No
DECT 6	1.9 GHz	Yes

The problem with many of the current cordless phones is the fact that the base station is sending signals (RF radiation) non-stop, 24 hours a day without being in use (stand-by mode). This effect raises the RF exposure to individuals in buildings significantly.

Measurements of 4 different cordless Phones

The author purchased four different types of cordless phones currently on the shelves of all major electronic warehouses. Random samples of different technology systems were selected. A spectrum analyzer (Rhode & Schwarz FSH3), a directional logarithmic periodic antenna (Schwarzbeck UKPL 9140) and a high frequency meter (Gigahertz HFW 35C) were used to conduct the testing.

Measurements were conducted at about a 3 feet distance (1 meter) from the base station and the handheld devices with the unit in use and in stand-by mode. The following table identifies the technology system, frequencies and the radiation levels.

Table 4: Measurement Results of 4 Cordless Phones

System	Name/Model	Frequency range	Permanent transmission	Power density nW/cm²
DECT 6.0	PanasonicKX-TG6311S	Base: 1.9 GHzHandheld 1.9 GHz	YesNo	200200
5.8 GHz FHSS	Panasonic KX-TG4321B	Base: 5.8 GHzHandheld: 5.8 GHZ	YesNo	200200
5.8 GHz DSS	VtechCS5111-2	Base: 0.9 GHzHanddeld: 5.8 GHz	NoNo	5020
5.8 GHz analog	GE25922FE1-A	Base: 5.8 GHzHandheld 0.9 GHz	NoNo	220

The results show that the 5.8 GHz DSS and analog technologies power the base station off while in stand-by mode and create low exposures during use. Therefore, knowledge of the fields and technology systems are helpful in selecting a cordless phone to create low EMF environments, i.e. a “greener” building.

Another Phone Measurement

A different type of digital 2.4 GHz cordless phone was placed on a workstation and measurements were made at different distances from the base station with the phone not in use (stand-by mode).

Table 5: Power Density Levels of a Cordless Phone Base Station

Distance	Power Density
1 foot	4,050 nW/cm2
20 inches	1,460 nW/cm2
3 feet	360 nW/cm2
6.5 feet	91 nW/cm2

Case Study

A client is concerned about the installation of a new cellular base station to be erected on the roof of a recreation center across the street from their house. The author was asked to assess the home prior to the installation. Table 6 shows the testing results and their sources.

Table 6: Measurement Results for Power Density in nW/cm² from different Sources

Location	800-900 MHz Cellular Phone Band	1.8-1.9 GHz Cellular PCS Band	2.4 GHz cordless Phone	Total
Family room	0.1 nW/cm2	0.1 nW/cm2	493 nW/cm2	493.2

The 2,4 GHz was the single source creating high RF radiation in the room.

Green Ratings Systems

Most of the current DECT 6 and 5.8 GHz phones carry the EPA Energy Star rating. Obviously, this rating is not related to RF emissions. The DECT manufacturers have created two kinds of RF reduction methods for their phones for the European market.

• “Radiation Reduced” units which power down but do not totally switch off while in stand-by mode (phone not in use)


• “Low Radiation” units which turn the base station off when the phone is not in use

The types of phones were introduced to address customer concerns and consumer demand.

The German Federal Department for Radiation Safety (Bundesamt für Strahlenschutz) and the Radiation Protection Commission (Strahlenschutzkommission) have the following recommendation criteria for “Low Radiation” labeled phones.

• Base station to power off or create a 100,000 fold reduction of transmission power during stand-by mode


• Demand selective transmission power adjustments for handheld unit


• Demand selective transmission power adjustments for base station


• Plug for headset on handheld unit


• Regulation of the transmission distance

Listed below is the EMF/RF rating systems for phones proposed by the German indoor environmental associations.

Wired phone without magnet in speaker (piezo electric technology)

Regular wired phones

! Analog cordless phones

!! Digital phones which power off base station in stand-by mode

!!! DECT phones which power off or provide 100,000 fold reduction at base station in stand-by mode

!!!! DECT phones which power down but by a factor of less than 100,000

!!!!! DECT phones which do not power down or turn off in stand-by mode

Unfortunately, most indoor environmental consultants in the Untied Sated are not even aware of these EMF and RF issues. With this lack of awareness, manufactures have not been confronted with a demand to provide low RF DECT phones in the US.

Conclusion

Our electromagnetic environment has significantly changed over the last decade. New technologies and the wireless world can expose us to unknown quantities of high frequency electromagnetic radiation.

Small household items, such as cordless phones, can become a significant source of RF radiation in indoor environments. The IESO is currently drafting an EMF measurement standard to be published as an ANSI Standard. Therefore, it is important that indoor environmental professionals, IAQA members and the IAQ industry be aware, familiar and able to assist their customers on EMF/RF issues. A “green” building should also be a low EMF/RF building to provide a healthy habitat. Alternative low emission technology is available to replace higher emission devices. These parameters should be part of a “green” building specification and should be evaluated when building-associated illnesses are investigated.

____________________________________

If you would like to learn more about detection and shielding of electromagnetic radiation exposure from cordless phones or other devices, call the experts at EMFRF Solutions today at 760-942-9400.

Read Additional EMF RF Articles:

• What is ElectroSmog?


• RF Radiation Study: How To Measure RF Exposure


• Is An iPad Radiation Shield For RF Shielding Effective?

Read the full story at: http://www.emfrf.com/how-green-is-your-cordless-phone-report/

How Much Electromagnetic Radiation Comes From A 2.4 GHz Cordless Phone? [Report]

How far does the RF radiation from your DECT cordless phone reach inside your home and how strong is it. A real-life study performed by us with a DECT cordless phone provides us with some answers. The paper was presented at the EMF Workshop in Rhodes, Greece in 2002.

Abstract

The use of DECT (Digital Enhanced Cordless Telecommunication) cordless phones has been a major health and environmental concern in Europe and especially in Germany for years. The biological concern arose from studies on HF (high frequency) sources such as GSM cellular phones and towers. Digital cordless phones are also available in the USA – marketed as 2.4 GHz digital technology. A digital cordless phone was placed in a representative private home in California and HF measurements were conducted at different locations inside, using frequency selective spectrum analysis to obtain the cordless phone power densities. The results showed that the radiation patterns and levels emitted by the small cordless phone base station are almost identical to the DECT technology – also digitally pulsed and permanent microwave radiation. The power density values presented for each room inside the home can be compared to average DECT cordless phone radiation exposures found in German homes. The maximum power density was found to be over 500,000 µW/m² at a normally encountered distance (about 1 – 2 feet) if the base station is placed on an office desk or bedside table. The radiation peak values in the same room are higher than those encountered in proximity to cellular base stations located near residential buildings.

Introduction

DECT cordless phones usage has been a major health and environmental concern in Europe and especially in Germany for years. Now multiple handsets cordless phones are also available in the USA – extolled as 2.4 GHz digital technology with multiple handsets following the DFHSS (Digital Frequency Hopping Spread Spectrum) standard which is almost identical to DECT. The biological concern arose from studies on high frequency (HF) sources such as cellular phones and cellular phone base stations with GSM technology. The digital pulsed pattern of GSM and DECT radiation has come under suspicion to cause e.g. brain cancer, lymphoma, and changes in the brain blood barrier. The problem with the cordless DECT phones is, that the base station permanently emits full power pulsed microwave radiation, whether the phone is used or not. This creates constant exposure to high levels of the most critical type of HF radiation known throughout the entire home or office. The DECT technology is a European standard for cordless phones in the range of microwave radiation (1.8 to 1.9 Gigahertz, GHz). Identical permanently emitting portable phones with the special option of multiple handsets are available in the US and therefore the exposure issues are relevant for US population. In the US, the cordless phone manufacturers established the 2.4 GHz digital pulsed technology in the range of 2.4 – 2.5 GHz. Cordless phones such as e.g. the GIGASET (same name as a DECT cordless phone series by the same manufacturer in Germany) are available in USA.

Methods

A GIGASET cordless phone model was selected as a representative DFHSS 2.4 GHz phone for typical home and office usage. The base station was purchased in the US and placed on a wooden office desk in a representative 3 bedroom residential building in California. In the first test set, the power density in the room was measured prior to the activation of the base station to obtain background levels at the test site. Power density measurements were performed at different distances and directions from the phone (see table 1 and 2) with an Advantest R4131C spectrum analyzer (Rohde & Schwarz) and a calibrated periodic logarithmic log.per. antenna UKLP 9140-A (Schwarzbeck). The power density measurements were conducted under real-life conditions and only peak values (pulse maximum) were measured. All measurements were conducted following VDB guideline (VDB 2002) and the Swiss BUWAL guideline (BUWAL 2002). The power density levels are given in µW/m² (microwatt per square meter). 1 µW/m² equals 0.1 nW/cm² (nanowatt per square centimeter). The background level was <0.3 µW/m² (-58 dBm) in the range of all wireless, analogue or digital cordless, and cellular phone applications (0.3 to 3.5 GHz). See figure 1.

Results

High frequency measurements were conducted and showed that the radiation patterns and levels emitted by GIGASET 2.4 GHz cordless phone base station are identical to the DECT technology – also digitally pulsed with permanent microwave radiation. For comparison, the radiation levels from the GIGASET located in the same room are even higher than encountered in proximity (50 to 100 feet) to most cellular base station located on pole mount positions or on top of office buildings. However, in this case the source of the radiation is a desktop personal cordless phone.

Figure 1: Spectrum analysis (no 2.4 GHz)	Figure 2: Spectrum analysis (with 2.4 GHz)

After the phone was plugged in, the radiation level rose to 673,000 µW/m² (+0.2 dBm) in a normally encountered distance (about 1 – 2 feet) if the base station is placed on an office desk. See figure 2. The following power density levels were obtained :

Table 1: 2.4 GHz cordless phone base station power density levels in the same room

*this study, **OEKO-TEST 1996

The results of the US GIGASET showed similar power densities when compared with the power densities reported for the GIGASET sold in Germany with DECT technology. Physical barriers such as e.g. wood framed walls, cabinets, closets have only a limited shielding effect inside a building. To evaluate a real life radiation exposure, the base station was placed on a desk in a bedroom (home office) and the actual power densities were measured in the different rooms. In this experimental test set, the real life effect of such a cordless phone installed in an average home and its associated radiation exposures were evaluated. The following values were obtained during our test set. The measurements showed a significant exposure for the occupants (see also table 2 and floor plan in appendix, figure 4)

Table 2: 2.4 GHz cordless phone base station power density levels in the house

	US GIGASET (2.4 GHz)*	GERMANY GIGASET (DECT)**
Distance	DFHSS (Digital Frequency Hopping Spread Spectrum) digital pulsed 100 Hz frequency range 2450 MHz	DECT (Digital Enhanced Cordless Telecommunication) digital pulsed 100 Hz frequency range 1880 MHz
30 centimeter – 12.5“	673,000 µW/m2	405,000 µW/m2
50 centimeter – 19.8”	280,000 µW/m2	146,000 µW/m2
1 meter – 39.4”	72,000 µW/m2	36,000 µW/m2
2 meter – 78.8“	23,000 µW/m2	9,100 µW/m2

Besides the permanent emission from such a base station, the pulsed nature of the signal was analyzed and is displayed in figure 3. The spectrogram shows the periodic pulsed signal. The dynamic range of the power density covers the full range scale from minimum (pause) to maximum (pulse) and is sending out pulses every 10 milliseconds (ms) or 100 Hz (Hertz).

Figure 3: Pulsed signal of 2.4 GHz DFHSS technology – ZERO SPAN

(GIGASET cordless phone base station)

Summary

The levels encountered are considerably high for an indoor source, which emits permanently. The radiation peak values in the same room are higher than those encountered in proximity to cellular base stations located at pole mount or roof top positions. Even in the master bedroom and in the second bedroom, the power density levels were in the range of or above the 95. percentile radiation level just recently obtained from a study of cellular phone tower measurements in residential areas (HAUMANN 2002). For comparison, thermal (guidelines), other non-thermal (recommendations), and cellular tower exposure reference values are listed in the table 3 below.

Table 3: Comparison of Standard Threshold Values and Recommendations

Room	Power Density (maximum pulse peak value)
Office with phone	33,800 µW/m2
Master bedroom	13,500 µW/m2
Bedroom 2	5,400 µW/m2
Bedroom 3	680 µW/m2
Living room	140 µW/m2
Family room	50 µW/m2
Outside	9 µW/m2

Many European researcher, physicians, environmental professionals and toxicologist signed a resolution requesting the immediate stop of the DECT technology. This petition was delivered to the Germany Environmental Minister Mr. Jürgen Trittin in October of 1999 (Resolution 1999). The Germany magazine “Oeko-Test” (equivalent to the US magazine Consumer Test) had 16 DECT cordless phones tested, published the measurement results, and rated all phones as not recommendable due to the constant emission of high levels of pulsed radiation (Oeko-Test 1999).

Conclusions

As long as the only base for official standards on high frequency radiation are thermal effects and heating of the body tissue (FCC, ICNIRP, ANSI, IEEE, NCRP) there is no need for the industry to invest into saver products. More and more scientists state that the view of energy absorption only is insufficient to describe the possible effects on human health. Potential biological effects need to be considered due to

1. Non-thermal or low intensity levels of HF radiation,


2. Chronic versus acute exposure and,


3. Pulsed HF radiation, which is reported to be more bioactive than constant wave HF radiation.

The human body reacts much more complex than acknowledged in the thermal model and is very sensitive to extreme periodic stimuli. The biological system takes the “energy” as well as the “information” which is brought e.g. by the continuous pulsed modulation pattern.

Much experimental evidence of non-thermal influences of microwave radiation on living systems has been published in the scientific literature during the last 30 years – relating both to in vitro and in vivo studies – and were reviewed just recently by the STOA commission of the European Parliament (STOA 2001). From the use of microwave wireless technologies e.g. the following non-thermal biological effects have been reported:

• Changes in the electrical activity in the human brain,


• 
  

  Increase in DNA single and double strand breaks from HF exposure to 2.45 GHz,

  
  


• 
  

  Increased lymphoma rates (2 fold) in transgenic mice exposed twice a day exposed to 30 minutes of cell phone (GSM) signals over 18 month,

  
  


• 
  

  Increased permeability of the blood-brain barrier in rats,

  
  


• 
  

  Observation of an increase in resting blood pressure during exposure,

  
  


• 
  

  Increased permeability of the erythrocyte membrane,

  
  


• 
  

  Effects on brain electrochemistry (calcium efflux),

  
  


• 
  

  Increase of chromosome aberrations and micronuclei in human blood lymphocytes,

  
  


• 
  

  Synergistic effects with cancer promoting and certain psychoactive drugs,

  
  


• 
  

  Depression of chicken immune systems,

  
  


• 
  

  Increase in chicken embryo mortality,

  
  


• 
  

  Effects on brain dopamine/opiate electrochemistry,

  
  


• 
  

  Increases in DNA single and double strand breaks in rat brain,

  
  


• 
  

  Stressful effects in healthy and tumor bearing mice,

  
  


• 
  

  Neurogenetic effects and micronuclei formation in peritoneal macrophage.

  
  

In this review study, a threshold of 1000 µW/m² was evaluated for non-thermal biological effects. For locations with any long-term exposure, a further safety factor of 10 was recommended for pulsed cellular phone radiation sources as cellular phone base stations. In this case, the power densities should not exceed 100 µW/m².

The constant High-Tec HF radiation brought into the US homes and offices by 2.4 GHz digital technology cordless phones is definitely a big step in the wrong direction in terms of environmental health protection and radiation exposure prevention. This reveals a complete misunderstanding of progress for our new millennium.

Read Additional EMF RF Articles:

• RF Radiation Study: How To Measure RF Exposure


• Is An iPad Radiation Shield For RF Shielding Effective?


• Cell Tower Shielding In San Diego

If you would like to learn more about detection and shielding of electromagnetic radiation exposure from cordless phones or other devices, call the experts at EMFRF Solutions to have your location tested and advice on how to properly shield from EMF or RF radiation. Call 760-942-9400 Today!

References

BUWAL 2002 Schweizer Messvorschrift für GSM-Sender 2002, BUWAL – Bundesamt für Umwelt, Wald und Landschaft. (www.buwal.ch)

Ecolog 2000 Hennies K., Neitzke H.-P. & Voigt H., Mobilfunk und Gesundheit – Bewertung des wissen­schaftlichen Erkenntnisstandes unter dem Gesichtspunkt des vorsorgen­den Gesund­heitsschutzes. Im Auftrag der T-Mobil. Hannover, April 2000 (ECOLOG-Institut für sozial-ökologische Forschung und Bildung, Nieschlagstr. 26, D-30449 Hannover, Germany)

Haumann 2002 Haumann Th., Sierck P., Maes W. and Münzenberg U., HF-Radiation of GSM Cellular Phone Towers in Residential Areas, in Biological Effects of Electromagnetic Fields 2nd International Workshop Rhodes, Greece / 7 – 11 October 2002 (submitted for presentation)

MAES 2000 Maes W., Stress durch Strom und Strahlung, 4. Ed. 2000, Verlag Institut für Baubiologie und Oekologie IBN, Neubeuern, Germany.

Oeko-Test 1996 Test “Schnurlose Telefone”, Öko-Test 3/1996 Germany, Maerz 1996. (www.oekotest.de)

Oeko-Test 1999 Test “Schnurlose Telefone”, Öko-Test 11/1999 Germany, November 1999.

Oeko-Test 2001 Test “Mobilfunk-Sendeanlagen”, Öko-Test 4/2001 Germany, April 2001, pp. 32 – 40.

Resolution 1999 Resolution for Bundesumweltminister Trittin, Germany, delivered on 19.10.1999 during the event “Buergerforum Elektrosmog” organized from the Bundesministerium für Umwelt, Naturschutz und Reaktorsicherheit in Bonn, Germany.

Resolution 2000 Salzburg Resolution on Mobile Telecommunication Base Stations – International Conference on Cell Tower Siting, Linking Science & Public Health, Salzburg, Austria, June 7-8, 2000. (www.land-sbg.gv.at/celltower)

SBM 2000 Baubiologie Maes and IBN, Standard der Baubiologischen Messtechnik SBM 2000, Richtwerte für Schlaf­bereiche, in “Stress durch Strom und Strahlung”, Maes W., 4th Ed. 2000, pp. 542 – 545, Verlag Institut für Baubiologie und Oekologie IBN, Neubeuern, Germany.

STOA 2001 THE PHYSIOLOGICAL AND ENVIRONMENTAL EFFECTS OF NON-IONISING ELECTROMAGNETIC RADIATION, STOA – Scientific and Technological Options Assessment, Options Brief and Executive Summary, PE Nr. 297.574 March 2001, (www.europarl.eu.int)

VDB 2002 VDB-Richtlinie, Teil II A 3, draft 2002, Verband Deutscher Baubiologen e.V. (www.baubiologie.net)

Appendix

Figure 4: Floor plan with exposure data

Figure 4: Floor plan with exposure data

Nonstop Pulsed 2.4 GHz Radiation Inside US Homes

Thomas Haumann¹ and Peter Sierck²

¹Umweltanalytik und Baubiologie,

Meisenburgstrasse 25, D-45133 Essen, Germany

²Environmental Testing & Technology, Inc.,

1106 Second Street, Encinitas CA 92024, USA

Read the full story at: http://www.emfrf.com/2-4-ghz-cordless-phone-radiation-report/

Comparison of Standard Threshold Values and Recommendations (electromagnetic fields, non ionizing radiation)	Total Power Density
Standards, > 2,000 MHz (e.g.)
FCC/ANSI – USA	10,000,000 µW/m2
Germany, England, Finland and Japan	10,000,000 µW/m2
Belgium	1,200,000 µW/m2
Switzerland and Italy	90,000 µW/m2
Recommendations / References (e.g.)
Ecolog Study, Germany (Ecolog 2000)	10,000 µW/m2
Cellular tower radiation – high exposure level, 95. percentile (Haumann 2002)	6,300 µW/m2
Salzburg, Austria (Resolution 2000)	1,000 µW/m2
EU Parliament (STOA 2001)	100 µW/m2
Cellular tower radiation – background level, 20. percentile (Haumann 2002)	15 µW/m2
Low exposure, Oeko-Test (Oeko Test 2001)	10 µW/m2
Nighttime exposure, Baubiology Standard (SBM 2000)	0.1 µW/m2
Natural cosmic microwave radiation (Maes 2000)	< 0.000001 µW/m2

Step-By-Step Smart Meter Measurement Protocol For RF Emissions

If you want to measure RF emissions from smart meters, we have developed smart meter measurement protocol in conjunction with Health Living Technologies. It provides a step-by step protocol for using a Gigahertz Solutions HF59B meter in conjunction with the NFA1000 data logger.

Introduction

Smart Meters are utility meters that transmit user data wirelessly via repeater stations to utility companies. These new meters are replacing the traditional electric, water and gas utility meters in order to tracking energy consumption electronically and remotely. Smart meters are currently installed throughout different states in the United States and in Canada. The Smart Meters relay consumption data back to the power utility companies, at various time intervals throughout the day. The primary method of sending this information back to the utility company is via radio frequency (RF) waves. Concerns about potential health effects from the radio frequency exposure from smart meters have been raised by individuals, scientists and organizations.

The Purpose

The purpose of this document is to provide a complementary measurement methodology for smart meter RF emissions. Traditional standard compliance measurements record the radiated power in 6 minute time averages. However, smart meter transmit only for milliseconds at a time and averaging will result in significantly lower values and may not depict the appropriate exposures level.

The instrumentation and methodology described in this protocol were developed after a pilot study with different RF instruments was utilized. It was noted that not all instruments were capable of providing the various aspects of measurement data required. The test results and measurement challenges have been described in a previously published technical paper entitled Smart Meter – What do we Know? The document can be downloaded at http://etandt.com/documents/SmartMeter-WhatWeKnow.pdf

Our goal was to utilize relatively cost efficient professional instrumentation, yet provides reliable, reproducible information on the radiated signal amplitude (power output), frequencies and rate of transmission (duty cycle). The authors of this guideline document are looking for input to improve the protocol and to add other instrumentation which fulfills the requirements.

Characteristic of Smart Meter Signals

Wireless Smart Meters receive and transmit data using a wireless network. The transmission occurs with a dipole antenna. These frequencies are similar to frequencies used in cellular phones, wireless computer networks, DECT cordless phones, baby monitors, Wi-Fi systems, and other wireless networks and devices. Smart meters use a technology, which is referred to as frequency hopping spread spectrum. That means the transmission frequency will change constantly during a given time period. Two or three different frequency bands are currently being utilized.

• 
  902-928 MHz (megahertz) band is mostly used for transmission to repeater units.
  


• 
  1.9 GHz (gigahertz) band can potentially be used for transmission to repeater units.
  


• 
  2.4 GHz band for future communication of appliance data via ZigBee or Wi-Fi network and in the transmission to the cellular network band.
  

The RF output from the meters is unique as information is transmitted in quick bursts lasting only milliseconds (ms) in time. Transmissions come in bursts with rates as often as every few seconds to once per hour, and can vary in frequency. The question is how do we measure them?

Measurement Challenges

Characterizing RF fields produced by Smart Meters can be difficult. The intermittent nature of the emissions means that it is not a simple matter of bringing an instrument to an installed meter and be able to instantly detect the presence of the various emissions. The smart meter may or may not be in a transmit mode at the time when measurements are sought. Further, the spread spectrum characteristic (frequency hopping) of the emissions leads to a further complication.

For example, the emitted signal, at any particular instant in time, may be on any specific frequency within the 902 to 928 MHz band. When using narrow-band instrumentation, such as a frequency swept spectrum analyzer, the challenge is to have the analyzer on the specific frequency at the very instant in time that the emission is occurring to be able to measure its signal strength (amplitude). Since the emissions are highly intermittent, this may take considerable time to insure that any such emissions have been captured by the instrumentation. These transmission rates are referred to as duty cycles. A 100% duty cycle corresponds to continuous operation, e.g. 24 hours/day. A 1% duty cycle corresponds to a transmitter operation of 1% per 24 hours.

Instrumentation and Methodology

These suggested measurement protocols use commonly available low cost professional RF instrumentation to assess the signal strength, time interval of transmission bursts and determination of the 900 MHz frequencies. We have found this instrument set-up to be successful in providing a good overview of the emission parameters. Improvement to the initial protocol can be made. Submission of suggestions from other parties is encouraged. The instrumentation used includes a broadband RF power meter to measure power density of output signals, a data logger to record RF power output and rate of transmission bursts, RF analysis software and a laptop computer.

Preliminary Set Up Selection

The first and most important step is the determination of the appropriate measuring range setting for the instrument. The instrument has three different power density range settings. See table below.

Before data logging begins, measurements with the HF59B should be conducted to determine the level of background RF radiation present. This will determine the best measurement range for logging the Smart Meter transmissions.

1. Apply the following settings on the HF59B switches.

Setting	Power Density Range
Maximum (coarse)	200 – 20,000 µW/m2
Medium (medium)	20 – 200 µW/m2
Minimum (fine)	0 – 20 µW/m2

Meter Switches	Switch Setting
Range	Max (20,000 µW/m2)
Video Bandwidth	VBW” – Standard
Signal Type	Full
Signal	Peak Hold
External Adapter	0 dB
Volume	Medium

2. Turn unit on. Hold or place the instrumentation approximately 2-3 feet horizontally from the Smart Meter to be tested and wait. When a transmission burst is detected an audible signal will occur. Record the value on the LCD display. Clear the display by depressing the clear button for 3-5 seconds. Repeat this procedure until 2-3 consistent readings have occurred and have been recorded. This process will provide an indication of what signal strength levels are expected during the data logging process.


3. If readings are:

Instrument Set Up

 

1. Connect the UBB27 isotropic probe to the HF59B RF power meter by inserting the probe into the front of the instrument and attaching the probe cable to the antenna input port.


2. Connect the NFA1000 to the HF59B RF power meter with a 2.5mm interface cable. Insert the cable into the DC output port of the HF59B and the AC/DC input port of the NFA1000.
   


3. Configure the HF59B and the NFA1000 as follows:

Greater than 20,000 µW/m²	Below 200 µW/m	Below 20 µW/m
A vertical bar, without any other values, will be displayed on the left side of the LCD display. This means that the signal strength was above the measurement range. If this is the case, attach the external attenuator (DG20_G3) to increase the power range and set the External Adapter Switch to the -20 dB setting. Repeat the previous procedure.	Switch the measurement scale to Medium and repeat the previous procedure.	Switch the measurement scale to Minimum and repeat the previous procedure.

4. If long term data logging is required (more than 2 hours) use the provided AC adapter and ensure ferrite beads are installed on the power adapter of NFA1000 as well as the HF59B.


5. Ensure that all nearby wireless devices are unplugged or turned off, such as cordless telephones, wireless internet routers and cell phones. Any active wireless devices near the testing area can significantly impact the smart meter measurement results.


6. Take the unit to the measurement location.


7. Attach the HFE59B with the probe to a tripod or a pedestal providing the right positioning for the measurement location. The NFA1000 should be located several feet away, below the HF59B. The tripod or supporting device should be non-metallic, if possible.
   


8. Place the HF59B horizontally at a minimum distance of 2 to 3 feet from the smart meter. This assures that the instruments are in the far field region. The 900 MHz range has a wave length of 33 centimetres. The far field starts at 2-3 wave length.


9. Power HFE59B on, by sliding the power switch to the top position. Check to see that the display is iluminated.


10. Power the NFA1000 on, by turning the power switch in the “log” position.


11. Make sure that the HF59B display shows numeric values. The NFA display will cycle through 3 different sets of information. The Log#, the length of the current log and the remaining battery life. Record the Log# displayed in your field notes. The log# on the meter will be displayed as L052 meaning log # 052. The recorded data is stored in the NFA1000 SD memory card with the current log file number. Eg. LOG00052.TXT


12. Let the configured instruments run until the measurement time period is completed. Allow the testing to run for several hours – the longer the better.


13. When testing is complete, power off the NFA1000 first by switching the power button form the Log position to the off position. After a few seconds power off the HF59B by switching the power button to the off position.


14. Take instrument assembly apart, store in cases.

Data Analysis by Software

1. Connect the NFA1000 via a USB port and cable to a PC. One can also remove the SD memory card and insert it directly into a card reader of a computer. The SD card will appear as a removable hard drive. Always remember to eject the SD card properly as any other USB device to avoid loss of data.


2. Run NFAsoft.140.exe, or later version, from the PC, or the SD memory card of the NFA1000.


3. Click the analyze data button
   

4. The following screen will appear

5. Select the appropriate Log File and click open.


6. The following screen will appear.


7. 
   Channel 4 by clicking the arrow to the left of its title.
   
   
   
   1. If another channel is open, it can be closed by clicking the arrow to the left of the channel title.
   
   
   2. Units of measurement for Chanel 4 is milliVolts “mV”.
      
   
   
   
   

• When logging, the recorded data is saved on channel 4 and the unit of measurement is in milliVolt (mV). This data needs to be converted to a power density reading in µW/m².

8. Right click on Channel 4. A dropdown menu will appear.


9. Click “Select HF Unit”

10. An HF unit conversion Box will appear.
    

11. Click the down arrow on the dropdown menu to reveal conversion options


12. Select the measurement range used for logging
    

For Example:

HF59B		NFA1000
Switches	Setting	Meter Switches	Switch Setting
Range	Max	Mode	Auto
Signal	Peak	Signal	TRMS
DC Output	1	Field Selection	M3D
VBW	Standard	Memory	SD memory card installed
Signal Type	Full
External Adapter	0 dB
Volume	Low to conserve power
Power	Battery mode will last approximately 2 to 3 hours	Power	Battery mode will last approximately 36 hours

Range	Selection
Max.	20.00mW/m2 or 20,000µW/m²
Med.	200.00µW/m²
Min.	20.00 000µW/m²

13. Select 1 V DC output (Default).


14. Click okay to complete data conversion.


15. A new HF window will now appear in red displaying the converted data in Power Density in µW/m²
    


16. Close Channel 4 by clicking on its down arrow to allow only your logged data to be visible. This is what you should see.

• y-axis – Power Density in µW/m²


• x-axis – Recorder Data plotted in µW/m²

Measurement Uncertainty

Every measurement is subject to uncertainties. Any official measurement report can only be considered to be complete when it includes the measurement uncertainties as well as the measurement results. Every factor that may influence the measurement result must be taken into account. The uncertainty associated with each of these factors also needs to be estimated. Generally, there are two possible sources of uncertainty or error: the measuring equipment and the person operating it.

Gigahertz Solutions calculates the maximum measurement uncertainty at +/-3dB which means the measurement result can be up to 100% above the measured value or 50% below. This is the worst case scenario and must be taken into account. This may seem high, but it is one of the best uncertainty values for standard RF test equipment on the market today.

For more information or products, please contact the authors listed below:

Peter Sierck,
Director/Industrial Hygienist
1106 Second Street, Suite 102 ▲ Encinitas, CA 92024 USA
760-804-9400 Office ▲ 760-942-9400 Direct Line ▲ 760-519-2271 Cellular
Email: psierck@etandt.com
Website: www.EMFRF.com

——————————————————————————————————————————

Rob Metzinger,

Electronics Engineering Technologist, BBEC
Gigahertz Solutions North American Importer / Technical Support / Equipment Warranty Provider
President
Safe Living Technologies Inc.
7 Clair Road West, PO Box 27051
Guelph On, N1L0A0
Canada
Tel: (519) 240-8735
Email: rob@slt.co
Website: www.slt.co

Links: EMF Meters / RF Meters

Read the full story at: http://www.emfrf.com/smart-meter-measurement-protocol/