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This paper provides an overview of the recommended procedure for performing electromagnetic field (EMF) or electro-magnetic radiation EMR measurements either by engaging a professional or by consumers using low-cost instruments which measure EMF exposure levels in gauss or milligauss.

See ENVIRO-SCARE, EMF & Property Values if you don't know what EMF, ELF, or electromagnetic fields are or if you want a summary of the possible health effects of EMF exposure and the more likely effect on the property value of homes located very close to power transmission lines. Readers who intend to make their own EMF measurements should be sure to also see WORKSHEET for EMF MEASUREMENTS and also WORKSHEET for EMF MEASUREMENTS - Example.

An Overview of an EMF/EMR Measurement Survey Procedure

Magnetic fields are directional; measurements are affected by position as well as location of the instrument within the area being examined, and by the distance of the instrument from the field source. Our field experience strongly suggests that results are quite variable depending on the particular direction aimed and positions held when using the measuring instrument.

Therefore, and consonant with recommendations from the manufacturers, each of our "measurements" is derived from at least three instrument readings, holding the instrument pointed at a suspected field source (e.g. nearby power line), pointed straight up, and held horizontally. Horizontal and vertical measurements are recorded as the highest obtained following a 360 degree scan of the area with the instrument held in that position.

During such a rotation in the presence of a strong magnetic field we find reading levels ranging widely. We warn you that measurements made by another professional will not duplicate our results unless our exact procedure is used with an instrument of similar performance at the identical locations. However our experience is that measurements with similar instruments in approximately the same locations and circumstances, produce results which are quite close.

For each instrument reading we record location, position, meter sensitivity settings, meter readings, and estimated distance to the suspected field source, if any. We also record observations of devices such as TV's or computers if they are seen operating nearby.

For the analog device measurements, actual meter readings are converted to milli/microgauss using tables provided by the instrument manufacturer based on the sensitivity range to which the instrument was set at time of use. A range of sensitivity settings are required to protect this very delicate instrument from being damaged by the fields being measured. The manufacturer describes a mathematical procedure which we follow to combine these data into a single field level number for an area being measured.

For the digital device measurements, actual measurements are read on the instrument in gauss or milligauss, depending on a field strength sensitivity selection on the meter.

Please do not contact us with a request buy EMF measuring equipment. We do not sell anything. To do so would be a conflict of interest for this website. These devices are readily available from many electrical equipment and home inspection equipment suppliers. See Evaluation of Low-Cost EMF Instruments where we describe several low-cost and reasonably accurate EMF measurement devices that are readily available.

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ENVIRO-SCARE, EMF & Property Values
ENVIRO-SCARE Defined, Effects
ENVIRO-SCARE Effects on Property Values
EMF MEASUREMENT PROCEDURES
EMF SURVEY PROCEDURE - Details
  Introduction to EMF Measurement
  EMF/EMR Measurement Procedure Overview
    EMF Variability
    Electrical Utility Workers & EMF Exposure
    EMF Instrument Sensitivity & Accuracy
    EMF Polarity & Shape Affect Measurements
    Distance from the EMF Source Affects Strength
    Time of day & Season Affect EMF Strength
  Local EMF Sources May Exceed Power Line Strength
  Recommended EMF Measurement Procedure
    Outside EMF Measurements
    Outside EMF Measurement Documentation
    Indoor EMF Measurements
    Other Indoor EMF Measurement Targets
    Workplace EMF Measurements
  EMF Measurement Documentation Details
  EMF Measurement Instrument Use
    Definitions of Gauss vs Milligauss
    Position-sensitive EMF Instrument Readings
  Interpreting Electromagnetic Field Strength EMF Survey
  Evaluation of Low-Cost EMF Instruments
    Accuracy & Calibration of EMF Instruments
    Calibration of EMF Instruments in the Field
    Calibration of EMF Instruments by Electric Company
    Descriptions of Low-Cost EMF Instruments
    F.W. Bell Model 4060 ELF Meter
    Safeco™ analog EMF ELF EMR meter
    Walker Scientific ELF-50D™ Digital EMF Meter
References for Electromagnetic Fields and Cancer
WORKSHEET for EMF MEASUREMENTS
WORKSHEET for EMF MEASUREMENTS - Example
WORKPLACE EXPOSURE to Electromagnetic Fields

References for Electromagnetic Fields and Cancer Risk/Carcinogenicity

• Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear About Environmental Issues - online document by DF
• A Procedure for Measuring EMF electromagnetic fields online document by DF
• Consumer Product Safety Commission, 800-638-CPSC.
• US Environmental Protection Agency, Office of Pesticides and Toxic Substances, TSCA Assistance Office (TS-799), 800-424-9065 or 202-554-1404.
• "Evaluation of Potential Carcinogenicity of Electromagnetic Fields," EPA Report #EPA/600/6-90/005B October 1990. EPA: 513/569-7562.
• "Biological Effects of Power Frequency Electric and Magnetic Fields" background paper, prepared as part of OTA's assessment of "Electric Power Wheeling and Dealing: Technological Considerations for Increasing Competition," prepared for OTA by Indira Nair, M. Granger Morgan, H. Keith Florig, Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213
• "Biological Effects of Power Line Fields," New York State Powerline Project. Scientific Advisory Board Final Report, July 1, 1987.
• "Extremely Low Frequency (ELF) Fields," Environmental Health Criteria 35. World Health Organization, Geneva, 1984.
• "Electric and Magnetic Fields at Extremely Low Frequencies: Interactions with Biological Systems. In: Non ionizing Radiation Protection, World Health Organization, Regional Office for Europe, Copenhagen, 1987.
• "Electric and Magnetic Fields from 60 Hertz Electric Power: What do we know about possible health risks?," Department of Engineering and Public Policy, Carnegie Mellon University, Pittsburgh, PA 15213 1989.
• "Electromagnetic Fields Are Being Scrutinized for Linkage to Cancer," Sandra Blakeslee, New York Times, Medical Science section, April 2, 1991
• Electromagnetic Field Exposure Limits: Australia (as an example data point): the Australian National Health and Medical Research Council (NHMRC) guidelines recommend the following limits of exposure:
  • Public exposure to magnetic fields 1,000 milligauss continuous or 10 000 milligauss for up to 2 hours/day
  • Occupational exposure to magnetic fields 5,000 milligauss (for a working day) or 50 000 milligauss for up to 2 hours/day
  • Public exposure to electric fields 5 kV/m continuous or 10 kV/m for up to 2 hours/day
  • Occupational exposure to electric fields 10 kV/m for a working day or 30 kV/m for 2 hours/day

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More Information on Building Diagnostic Inspections and Repairs

• Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues
• Electromagnetic Fields in the Workplace sample very good NIOSH document online, links to other NIOSH docs.

• Environmental Concerns in Buildings, hazards: allergens, asbestos, brownfields, - above ground or buried oil storage tanks, - A Procedure for Measuring EMF electromagnetic fields, - Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues - toxic gases & odors, IAQ, lead paint, - toxic mold inspections, - mold test kits - how to send a mold sample to our lab using an inexpensive and superior method - radon, sick buildings, UFFI (urea formaldehyde foam insulation), - sewage septic backup contamination testing & cleanup - water testing for bacteria, lead, etc.
• Electromagnetic Field Surveys & Hazards full list of our links to services and technical articles

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