Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ENVIRONMENTAL HAZARDS - INSPECT, TEST, REMEDY
AIR FILTERING STRATEGIES
AIR POLLUTANTS, COMMON INDOOR
AIR QUALITY IMPROVEMENT STRATEGIES
AIRBORNE PARTICLE ANALYSIS METHODS
ALLERGEN TESTS for BUILDINGS
ANIMAL or URINE ODOR SOURCE DETECTION
ASBESTOS IDENTIFICATION IN BUILDINGS
ATTORNEYS and EXPERT WITNESSES
BACKDRAFTING HEATING EQUIPMENT
BIBLIOGAPHY for ENVIRONMENTAL HEALTH, MOLD, IAQ
BLACK MOLD, HARMLESS COSMETIC
BLACK MOLD, TOXIC & ALLERGENIC
BOOKSTORE - ENVIRONMENTAL
BUILDING SAFETY HAZARDS GUIDE
Cadmium in the home
CARBON MONOXIDE - CO
Carbon Nanotube Hazards
CARPETING & INDOOR AIR QUALITY
CHEMICAL CONTAMINANTS in WATER
CHINESE DRYWALL HAZARDS DS
COMBUSTION PRODUCTS & IAQ
CPSC Indoor Air Pollution Book Online Copy
DIRECTORY of MOLD / ENVIRONMENTAL EXPERTS
Diethylstilbestrol - DES
DUST SAMPLING PROCEDURE
EMERGENCY RESPONSE, IAQ, GAS, MOLD
EMF ELECTROMAGNETIC FIELDS & HUMAN EXPOSURE
ENVIRO-SCARE - PUBLIC FEAR CYCLES
ENDOCRINE DISRUPTERS at BUILDINGS
FEAR of MOLD - MYCOPHOBIA
FLAME COLOR, BLUE vs YELLOW COMBUSTION
FLOOD DAMAGE ASSESSMENT, SAFETY & CLEANUP
FLOOR TILE ASBESTOS IDENTIFICATION
GAS EXPOSURE EFFECTS, TOXIC
GAS EXPOSURE LIMITS & STANDARDS
HEATING OIL EXPOSURE HAZARDS, LIMITS
HOME HEATING SAFETY
INDOOR AIR QUALITY & HOUSE TIGHTNESS
INDOOR AIR QUALITY IMPROVEMENT GUIDE
LEAD POISONING HAZARDS GUIDE
LEGIONELLA LEGIONNAIRES' DISEASE t
LIGHT, GUIDE to FORENSIC USE
GAS LP & NATURAL GAS SAFETY HAZARDS
METHANE GAS SOURCES
MSDS Material Safety Data Sheets
MYCOPHOBIA, STAINS MISTAKEN for MOLD
MYCOTOXIN EFFECTS of MOLD EXPOSURE
ODORS GASES SMELLS, DIAGNOSIS & CURE
OIL, HEATING, EXPOSURE HAZARDS, LIMITS
PARTICLE SIZES & IAQ
Particulates & Allergens Indoors
PESTICIDE EXPOSURE HAZARDS
PET ALLERGENS / PET DANDER
PLASTIC ODORS-SCREENS, SIDING
PLUMBING SYSTEM ODORS
PVC - VINYL BUILDING PRODUCTS
RADON HAZARD TESTS & MITIGATION
SAFETY HAZARDS GUIDE
SAFETY HAZARDS & INSPECTIONS
METHANE GAS HAZARDS
SEWAGE BACKUP TEST & CLEANUP
SICK HOUSE IAQ QUESTIONNAIRE
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on BUILDING INTERIORS
UFFI UREA FORMALDEHYDE FOAM INSULATION
VENTILATION in BUILDINGS
VINYL CHLORIDE HEALTH INFO
VINYL Siding or Window PLASTIC ODORS
VOCs VOLATILE ORGANIC COMPOUNDS
WATER ODORS, CAUSE CURE
WATER TESTS, CONTAMINANTS, TREATMENT
WORLD TRADE CENTER 9-11 DUST PHOTOS
EMF measurement instrument sensitivity & accuracy: this article explains the sensitivity and accuracy of EMF or ELF measuring instruments used for performing electromagnetic field (EMF) or electro-magnetic radiation EMR measurements to measure EMF exposure levels in gauss or milligauss. We discusses sources of error and variation in EMF measurements and we review and make suggestions for using several low-cost EMF measurement devices to determine the instantaneous electromagnetic field exposure.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
Because RF and EMF measurement tools need to be properly chosen to measure the particular type and frequency of RF or EMF signal that is of interest, be sure to also see EMF RF FIELD & FREQUENCY DEFINITIONS for a simple explanation of different types of radio frequency (RF) and electromagnetic frequency (EMF) types and where they are found. Also see Definitions of Gauss vs Milligauss for details about gauss and milligauss and definitions of these terms
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 EMF MEASUREMENT WORKSHEET and also WORKSHEET for EMF MEASUREMENTS - Example.
Most hand-held low-cost EMF measuring instruments (see our list at Evaluation of Low-Cost EMF Instruments) can make measurements down to 1 milligauss. Because it is common for us to find background EMF levels of 1-3 milligauss in residential neighborhoods where local electrical power distribution lines and transformers are present, and because some studies examined EMF field strengths down to this low level, a do-it-yourself EMF measurement project should probably avoid using instruments that lack that level of sensitivity.
But as we explain next, an accurate, sensitive EMF instrument is insufficient for making accurate and repeatable EMF measurements.
Inconsistency in EMF measurement methods is a problem: In order to permit comparison of measurements (and studies) it is important not only to have line load data available (for researchers) but also that site measurements are made in a very consistent manner from building to building.
To do otherwise would make it impossible to compare conditions at one property with those at another, even if both properties are equidistant from the same power line and even if both measurements were made at the same moment.
Position-insensitive EMF Measurement Instruments - best for the amateur
Position-sensitive EMF Measuring Instruments - Why and How They are Used
Electromagnetic fields are created around power transmission lines by the passage of high levels of current through the transmission line wires themselves. A power-line generated electromagnetic field has polarity and shape, roughly spherical around a power line.
The problem of the electromagnetic field having polarity and shape means that some early or low-cost EMF measuring devices will give widely varying field strength measurements depending simply on the physical orientation of the device when the measurement is made - that is, what direction you point the instrument affects its reading.
But don't think that pointing directly towards the power line wires overhead gives the maximum reading.
It may not, due to field polarity. More costly EMF meters have multiple sensors to overcome this defect.
We discuss the problem of electromagnetic field shape, polarity, and instrument testing sensitivity to instrument orientation or position at Sensitivity & Accuracy of EMF Measuring Instruments.
Please do not contact us with a request buy EMF or RF 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 This article describes several low-cost and reasonably accurate EMF measurement devices that are readily available. See Radio Frequency RF Detection Meters This article describes several low-cost and accurate radio frequency or RF detection and measurement devices suitable for radio, TV, cellphone, microwave, and similar signals.
Instead of contacting us with a request to perform EMF Electromagnetic or RF Radio Frequency Field Strength measurements, in most cases it is more economical and convenient for a property owner to purchase their own instrument, making measurements under varying conditions. In this series of articles we describe how to make measurements using a consistent approach and using good documentation. See Recommended EMF Measurement Procedure for details of how to collect EMF measurement data.
Following good procedure and using instruments properly are two steps towards making accurate, repeatable EMF measurements. But because the signal transmission for RF sources such as radio, TV, or cell towers, the load on a power transmission line is not under control of an individual property owner, and because the EMF strength varies as the power transmission line load varies, it is important to have an idea of that condition as well when attempting to characterize EMF exposure at a specific location. In contrast, EMF measurements are quite accurate and repeatable at other EMF sources such as close to electrical appliances and service entry cables.
Green link shows where you are in this article series.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Questions & answers or comments about how to hold, position, & use EMF field strength measurement instruments to account for variations in sensitivity and accuracy of Instruments for EMF power line and other source surveys.
Check the FAQs just above, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.