EMF measurement requires the right tools and understanding of what you’re measuring. Before purchasing an EMF meter, it’s crucial to understand which types of EMFs you need to measure, as different meters have different capabilities.
What Are EMFs?
EMFs (electromagnetic fields) are created by the movement and accumulation of electrically charged particles. While EMFs occur naturally (like the Earth’s magnetic field), modern technology has introduced many artificial sources into our environment, from power lines to wireless devices.
4 Different Types of EMFs
Most EMFs can be measured with a single high-quality EMF meter like the Trifield TF2 or GQ-390, which can detect electric fields, magnetic fields, and radio frequencies.
Only dirty electricity requires a separate specialized meter like the Greenwave Broadband EMI dirty electricity meter for measurement.
1. Electrical Fields
Created by voltage (electrical pressure) and measured in volts per meter (V/m). These fields exist whenever voltage is present, whether or not current is flowing.
2. Magnetic Fields
Generated by moving electric current and measured in gauss (G) or tesla (T), with milligauss (mG) being the most common unit for household measurements.
3. Radio Frequency (RF) fields
These are electromagnetic waves in the frequency range of 3 kHz to 300 GHz, measured in microwatts per square meter (µW/m²). Common sources include WiFi, cell phones, and bluetooth devices.
4. Dirty Electricity
Also known as electrical noise or line noise, these are high-frequency voltage transients on electrical wiring, typically measured in Graham-Stetzer (GS) units.
EMF Measurement Fundamentals
EMFs can be characterized by several parameters:
- Frequency (Hz) – oscillations per second
- Amplitude – maximum field strength
- Wavelength – distance between wave peaks
- Polarization – field orientation
- Phase – wave position in its cycle
- Power density (for RF) – energy per unit area
What EMF Meters Actually Measure
A typical EMF meter primarily measures field strength (amplitude) and sometimes frequency, but not all parameters. Here’s what consumer-grade EMF meters can typically detect:
Definitely Measures
- Amplitude (field strength)
- Magnetic fields: measured in milligauss (mG)
- Electric fields: measured in volts per meter (V/m)
Sometimes Measures (Model Dependent)
- Frequency (Hz): More advanced meters can detect frequency ranges
- Power density: Mainly for RF EMF meters
- Measured in watts per square meter (W/m²)
- Or milliwatts per square centimeter (mW/cm²)
Does Not Typically Measure
- Wavelength (typically calculated rather than directly measured)
- Polarization (requires specialized equipment)
- Phase (requires sophisticated oscilloscopes or specialized equipment)
Most consumer EMF meters focus on measuring field strength, with some models offering frequency detection within specific ranges. For more complex measurements like polarization or phase, an EMF specialist or professional-grade equipment designed specifically for those parameters would be required.
Safety Guidelines and Standards
Building Biology guidelines recommend the following levels, especially for sleeping areas:
- RF radiation: < 10 µW/m²
- Electric fields: < 1 V/m
- Magnetic fields: < 0.2 mG
How to Measure EMF Fields in Your Home
Measuring EMFs accurately requires the right tools and techniques. Let’s look at how to measure each type of field. For accurate measurements across all fields, you might want to consider the Trifield TF2 or GQ-390 meters. Here’s a guide to measuring each type of EMF:
Measuring Magnetic Fields
- Set your EMF meter to measure magnetic fields (usually measured in milligauss or nanotesla)
- Hold the meter at waist to chest height
- Move slowly through each room, paying special attention to:
- Areas near large appliances
- Places where electrical wires enter the home
- Spaces near your electrical panel
- Areas under or near power lines
- Take measurements in several spots in each room, as magnetic fields can vary greatly over short distances
- Make note of readings above 1 milligauss (100 nanotesla), as these might need attention
Measuring Electric Fields
- Switch your meter to electric field mode (usually measured in V/m)
- Important: Hold the meter with your arm extended to minimize body interference
- Check these key areas:
- Near bedding and sleeping areas
- Around electrical cords, even when devices are turned off
- Near walls with electrical wiring
- Around ungrounded electrical equipme
- Pay special attention to readings above 10 V/m in sleeping areas
- Consider measuring with and without devices plugged in to identify sources
Measuring Radio Frequencies
- Set your meter to RF mode (usually measured in microwatts per square meter – µW/m²)
- Remember to stay at least 3 feet away from sources like smart meters for accurate readings
- Measure in these important locations:
- Near WiFi routers
- Around smart meters
- In bedrooms
- Near cordless phone base stations
- Around baby monitors
- Take measurements at different times of day, as RF levels can fluctuate
- For smart meters, measure at 3 feet and 8 feet distances for comparison
Testing for Dirty Electricity
For measuring dirty electricity, you’ll need a special meter designed for this purpose. Follow these steps:
- Plug the dirty electricity meter into various outlets throughout your home
- Record readings in different rooms
- Pay special attention to outlets near:
- Dimmer switches
- Solar inverters
- Smart meters
- LED or CFL bulbs
- Consider installing dirty electricity filters in areas with high readings
- Re-test after installing filters to confirm improvement
Tips for Accurate Measurements
- Take measurements at different times of day
- Record your findings to track changes over time
- Consider measuring with and without certain devices operating
- Keep the meter steady while taking readings
- Make sure your meter is calibrated and has fresh batteries
- Follow the manufacturer’s instructions for your specific meter
Remember, while these measurements can give you valuable information about EMF levels in your home, interpreting the results and deciding on appropriate actions might require consultation with an EMF specialist, especially if you find concerning readings.
Sources of EMFs
In our modern environment, EMF sources are nearly ubiquitous. While some sources like the Earth’s magnetic field are natural and have been part of our environment throughout human evolution, the vast majority of EMF exposure today comes from human-made sources.
Understanding these sources is crucial for both measurement and mitigation strategies. You can read my post on the most common sources of EMF in your home here.
Common sources include:
- Power lines and electrical wiring
- Electronic devices and appliances
- Wireless communication equipment
- Solar power inverters
- Transformers and electrical panels
- Medical devices (MRI machines, X-ray equipment)
- Natural sources (Earth’s magnetic field, solar radiation)
EMF Protection Methods
Protection strategies should be based on accurate measurements and implemented in order of effectiveness:
- Distance
- The most effective and free method
- Field strength decreases rapidly with distance
- Follow the inverse square law for RF sources
- Avoidance
- Limit use of EMF-producing devices
- Power off devices when not in use
- Use airplane mode when possible
- Shielding
- EMF shielding materials (when properly grounded)
- Faraday cages for specific applications
- Proper installation is crucial for effectiveness
- Circuit Modifications
- Proper grounding
- Installing dirty electricity filters
- Correcting wiring errors
Best Practices for EMF Testing
- Regular Monitoring
- Establish baseline measurements
- Document changes over time
- Test at different times of day
- Professional Assessment
- Consider professional testing for:
- New home purchases
- Complex EMF environments
- Health concerns
- Legal documentation
- Consider professional testing for:
- Equipment Maintenance
- Regular meter calibration
- Battery maintenance
- Following manufacturer guidelines
Conclusion
Understanding and measuring EMFs in your home is a valuable skill that can help you make informed decisions about your environment. While the process may seem complex at first, breaking it down by field type – magnetic, electric, RF, and dirty electricity – makes it manageable. Remember these key points:
- Most EMFs can be measured with a single quality meter like the Trifield TF2 or GQ-390
- Regular testing helps establish baseline readings and identify changes
- Focus first on sleeping areas and spaces where you spend the most time
- Distance is your best protection – move sources away when possible
- Some solutions are free and simple, like unplugging devices when not in use
- Keep a log of your measurements to track changes over time
Start with basic measurements and expand your testing as you become more comfortable with your equipment. While DIY measurements can provide valuable insights, complex situations may require professional expertise for proper assessment and mitigation strategies. Professional EMF consultants have advanced equipment and expertise to handle challenging scenarios like:
- Multiple overlapping EMF sources
- Hard-to-access areas
- Complex wiring issues
- High-voltage power lines nearby
- Industrial equipment
- Professional office environments
By following this guide and maintaining regular testing habits, you’ll be well-equipped to monitor and manage EMF levels in your home environment.
How To Use An EMF Meter
Here is a great video showing how to use a EMF meter. The one is the video is my favourite meter the Trifield TF2 and you can read my review of the Trifield TF2 here.
References
https://www.emfs.info/what/measuring/
https://healthybuildingscience.com/2013/05/30/how-to-measure-emf/
