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EMF household appliance - City University of Hong Kong

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Human exposure requirement for Household Appliance Presented By Wilson Loke 21 June 2008 Page 2 of 13 emitel AG •Ohmstrasse 1 •94342 Strasskirchen •GERMANY Background Test Requirement and Standard Evaluation Method and limit Measurement method Example: Induction Cooker Background EMF (Electromagnetic Fields) EMF of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All 21 June 2008 Page 3 of 13 emitel AG •Ohmstrasse 1 •94342 Strasskirchen •GERMANY WHO (World Health Organization) WHO is the directing and coordinating authority for health withi n the United Nations system. It is responsible for providing leadershi p on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence-based policy options, providing technical support to countries and monitoring health trends. In the 21 st century, health is a shared responsibility, involving equitable access to essential care and collective defence against transnational treats. populations are now exposed to varying degrees of EMF, and the levels will continue to increase as technology advances. Background Standards and Guidelines A number of national and international organizations have formul ated guidelines establishing limits for occupational and residential EMF exposure. The exposure limits for EMF fields developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) – a non-government organization formally recognised by WHO, were developed following reviews of all the peer-reviewed scientific literature including thermal and non-thermal effects. The standards are based on evaluation of biological effects that hav e been established to have health consequences. The main conclusio n from the WHO reviews is that EMF exposures below the limits recommended in the ICNIRP international guideline do not appear to have any known consequence on health. International EMF Project WHO projects is to assess health and environmental effects of ex posure to static and time varying electric and magnetic fields in the frequency range 0-300GHz. http://www.who.int/peh-emf/project/EMF_Project/en/index.html 21 June 2008 Page 4 of 13 emitel AG •Ohmstrasse 1 •94342 Strasskirchen •GERMANY Background 21 June 2008 Page 5 of 13 emitel AG •Ohmstrasse 1 •94342 Strasskirchen •GERMANY Low Voltage Directive (2006/95/EC) LVD is the directive to ensure that electrical equipment within certain voltage limits both provides a high level of protection for European citizens and enjoys a Single Market in European Union. For most electrical equipment, the health aspects of emission of Electromagnetic Fields are also under the domain of Low Voltage Directive Harmonized Standard for the EMF under 2006/95/EC EN 50364:2001 Limitation of human exposure to electromagnetic fields from devices operating in the frequency range 0Hz to 10GHz, used in Electronic Articles Surveillance (EAS), Radio Frequency Indentification (RFID) and similar application EN 50371:2002 Generic standard to demonstrate the compliance of low power electronic and electrical apparatus with the basic restrictions related to human exposure to electromagnetic fields (10 MHz – 300 GHz) – General public EN 50366:2003 Household and similar electrical appliance – Electromagnetic fields – Method for evaluation and measurements Test Requirement and standard 21 June 2008 Page 6 of 13 emitel AG •Ohmstrasse 1 •94342 Strasskirchen •GERMANY EN 50366:2003 Household and similar electrical appliances – Electromagnetic fields – Methods for evaluation and measurement Defines methods for evaluating the electric field and the magnetic field for frequencies up to 300 GHz around household and similar electrical appliance Electric field: deem to comply with reference levels without testing for appliance. Magnetic field: 10Hz to 400 kHz, above 400 kHz deem to comply without test.
Transcript

Human exposure requirement for Household Appliance

Presented By Wilson Loke 21 June 2008 Page 2 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Background

Test Requirement and Standard

Evaluation Method and limit

Measurement method

Example: Induction Cooker

Background

EMF (Electromagnetic Fields)EMF of all frequencies represent one of the most common and fastest growing environmental influences, about which anxiety and speculation are spreading. All

21 June 2008 Page 3 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

WHO (World Health Organization)WHO is the directing and coordinating authority for health withi n the United Nations system. It is responsible for providing leadershi p on global health matters, shaping the health research agenda, setting norms and standards, articulating evidence- based policy options, providing technical support to countries and monitoring health trends.In the 21s t century, health is a shared responsibility, involving equitable access to essential care and collective defence against transnational treats.

populations are now exposed to varying degrees of EMF, and the levels will continue to increase as technology advances.

Background

Standards and GuidelinesA number of national and international organizations have formul ated guidelines establishing limits for occupational and residential EMF exposure. The exposure limits for EMF fields developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) – a non -government organization formally recognised by WHO, were developed following reviews of all the peer-reviewed scientific literature including thermal and non-thermal effects. The standards are based on evaluation of biological effects that hav e been established to have health consequences. The main conclusio n from the WHO reviews is that EMF exposures below the limits recommended in the ICNIRP international guideline do not appear to have any known consequence on health.

International EMF ProjectWHO projects is to assess health and environmental effects of ex posure to static and time varying electric and magnetic fields in the frequency range 0- 300GHz.http://www.who.int/peh- emf/project/EMF_Project/en/index.html

21 June 2008 Page 4 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Background

21 June 2008 Page 5 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Low Voltage Directive (2006/95/EC)LVD is the directive to ensure that electrical equipment within certain voltage limits both provides a high level of protection for Euro pean citizens and enjoys a Single Market in European Union.For most electrical equipment, the health aspects of emission ofElectromagnetic Fields are also under the domain of Low Voltage Directive

Harmonized Standard for the EMF under 2006/95/EC

EN 50364:2001 Limitation of human exposure to electromagnetic fields from devices operating in the frequency range 0Hz to 10GHz, used in Electroni c Articles Surveillance (EAS), Radio Frequency Indentification (RFID) and similar application

EN 50371:2002 Generic standard to demonstrate the compliance of low power electronic and electrical apparatus with the basic restrictions related to human exposure to electromagnetic fields (10 MHz – 300 GHz) – General public

EN 50366:2003 Household and similar electrical appliance – Electromagnetic fields –Method for evaluation and measurements

Test Requirement and standard

21 June 2008 Page 6 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

EN 50366:2003Household and similar electrical appliances – Electromagnetic fields –Methods for evaluation and measurement

Defines methods for evaluating the electric field and the magnetic field for frequencies up to 300 GHz around household and similar electrical appliance

Electric field: deem to comply with reference levels without testing for appliance.Magnetic field: 10Hz to 400 kHz, above 400 kHz deem to comply without test.

Evaluation method and limit

Time Domain Evaluation (Reference method and in case fo doubt)Time Domain Evaluation (Reference method and in case fo doubt)

21 June 2008 Page 7 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

separate measurement of each coil signal in three orthogonal di mensionweight of signal by the transfer functionsquaring the signaladding the squared signalsaveraging the sum of squared signalsobtaining the square root of the average

Evaluation method and limit

21 June 2008 Page 8 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

RL

smrc

BBra

W ...1)(=

WhereW is the weighted resultBr.m.s. is the r.m.s. of magnetic flux densityBRL is the reference level of the magnetic density at 50HzAc(r1) is the coupling factor given in Annex A

Limit: W shall not exceed 1

Evaluation method and limit

21 June 2008 Page 9 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Line spectrum evaluation (only line spectra shown)Line spectrum evaluation (only line spectra shown)

separate measurement each coil signalFourier transformation for each signal to obtain

the estimated spectrumVector addition of three spectra for each

discrete frequency

This method may be used when there are only line spectra.The magnetic flux density is measured at each relevant frequency.

222zfyfxff BBBB ++=

=

n

RLf

f

BB

W1

2

whereBf is the magnetic flux density at frequency fBxf, Byf and Bzf are the individual flux densities of the three coils at any one freqency

whereW is the weighted result;BRLf is the reference level of the magnetic flux density at frequency f obtained from Annex Bn is number of relevant frequency

Limit: W shall not exceed 1

Evaluation method and limit

21 June 2008 Page 10 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Simplified test methodsSimplified test methods

Mains frequency dominated to produce the magnetic fieldKnow the current producing the magnetic fieldharmonics current higher than 10% of mains current decrease continuous over

rangemagnetic flux density of 50Hz < 30% of reference level or magnetic flux density of

50Hz < 50% of reference level provided that harmonic magnetic flux density < 15% of reference level

Basic RestrictionBasic RestrictionThe minimum requirement of the electromagnetic field exposure from 1999/519/EC

Reference levelReference levelThe reference level developed from the basic restriction under 1999/519/EC

Measurement method

21 June 2008 Page 11 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

distance of the senorlocation of the sensoroperation conditions

Measurement SetupMeasurement Setup

Magnetic flux sensorMagnetic flux sensor

three direction100 cm2

mutually perpendicular concentric coilOutside diameter < 13cm

Measurement Uncertainty: 25%Measurement Uncertainty: 25%

NARDA ELT - 400

Example: Induction Cooker

Measurement LocationMeasurement Location

0.5m below the surface of induction cooker up to 1m above the surface

Test ConditionTest ConditionSmall recommended vessel is used

110mm, 145m, 180mm, 210mm and 300mm

50% water filled (measured at water boil)

Higest power in turn with each zone.

Measuring distanceMeasuring distance30cm from the induction cooker on four side

21 June 2008 Page 12 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY

Q & AQ & A

21 June 2008 Page 13 of 13emitel AG • Ohmstrasse 1 • 94342 Strasskirchen • GERMANY


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