Tag Archives: Austin

Why A Professional Digital EMF Meter Should Be Used For a Survey

In my previous post, I commented on a recent phenomena this past year in which a number of customers who had purchased an EMF meter online or elsewhere to do a survey on a prospective property contacted me after finding what appeared to be anomalously high readings and wanted a second opinion.

Every time it was a Trifield 100XE which is easily recognizable with the yellow label, brick-like construction and familiar needle movement which distinguishes it as an analog meter versus the digital EMF versions. The variations in accuracy varied from moderate to extreme when compared with my 3-axis professional grade meter and I began to wonder what was going on.

I recently contacted the manufacturer of the Trifields (AlphaLab Inc.) and one of their electrical engineers cleared up the mystery as to why the readings seemed to vary so wildly. The 100XEs are typically sold as frequency weighted which means that even slightly higher frequency magnetic fields will add even more to the indicated reading than a meter with a “flatter” frequency response. Also, they measure from 40 Hz – 100 KHz which is a VERY broad band for an AC gaussmeter used in a EMF survey for testing the influence of power lines. Typically, for measuring 60 Hz and any relevant power harmonics, an EMF meter that measures in the range of 30 Hz – 3 KHz is a broad enough range and even 30 Hz – 300 Hz will cover 60 Hz plus the 5th harmonic. The strength of the harmonics gets progressively weaker as frequency increases.

60 Hz Power Line Harmonics

60 Hz Power Line Harmonics

In other words, you may have a 3 milliGauss magnetic field at 60 Hz, but a weaker magnetic field at 120 Hz will weight the reading even more strongly and register as 6 milliGauss when in fact it is only 3 mG.  (from an excerpt on the company website) So the standard Trifield 100XE weights the “harmonics” (multiples of 60 Hz such as 120 Hz, 180 Hz, etc.) differently than a flat frequency EMF meter. Ordinarily, any instrument that is frequency weighted has an attendant chart which tells you how much more weight at different frequencies is measured than over the non-weighted frequency point of the meter.

Below is an example of this sort of chart for the Natural EM Meter (blue label) which is very different from the 100XE model. (This was taken from the vendor website – I know the word “frequency” is misspelled)

EMF Meter Frequency Magnetic Field

Natural EM Meter (not 100XE) Frequency Weighting Chart

A little confusing?

Based on my experience, I can interpret the chart, but what I wanted was the chart for the 100XE model Trifield and I could not find it on the manufacturer’s website. This is what initiated the call to the vendor. When I spoke with an electrical engineer, she explained that the 100XE is not particularly accurate (rated as +/- 20% according to the specs on their website) and is not recommended as a reference for any type of serious EMF survey.

Furthermore she went on to explain that even the manufacturer has NO SUCH chart for the 100XE model so you really don’t know what you are reading and how much is due to the 60 Hz magnetic field that you are interested in and how much is distorted or misrepresented by the high frequency harmonics.

And to further dispel another myth, the Trifield is named for the fact that it measures 3 types (tri) of fields: magnetic, electric and radio frequency, NOT because it is a 3-axis meter in every mode as the RF (radio frequency) measurement is only in SINGLE or 1-axis and will alter greatly depending on the orientation of the meter with respect to the RF source.

But I am not disparaging the company at all (they make some excellent equipment for certain applications and their website is very informative) and the 100XE has some viable uses, but it seems to be more towards something more subjective like the paranormal field rather than what a serious EMF consultant would choose for an official EMF testing survey. I DO like the needle movement as it does help you to track slow or fast fluctuations so I do keep a Trifield with me, but the difference is that I know under what circumstances it can be used and also when I would not use it as an absolute for helping a client decide on a property decision because of the proximity of power lines.

Counties & Cities Served by ScanTech Technical Consulting

Service Cities for EMF – Indoor Air Quality Testing Smart Meter – RF (Radio Frequency) inspection services include: Plano, Highland Park, University Park, Park Cities, Arlington, Fort Worth, Grapevine, Frisco, Denton, McKinney, Allen, Lewisville, Irving, Mesquite, Bedford, Euless, Richardson, Coppell, Grand Prairie, Garland, Addison, Farmers Branch, Rockwall, Carrollton, Parker, Rowlett, Lucas, Fairview, Park Cities, Keller, Roanoke, The Colony, Highland Village, Lake Dallas, Corinth, Prosper, Austin, Houston, Round Rock, Spring, The Woodlands, Bastrop, Duncanville, Lancaster, Rowlett, Royse City, Trophy Club, Southlake and Hurst. Counties served include Dallas, Collin, Denton, Tarrant, Travis, Harris and Rockwall County.

ScanTech EMF & Radon Service Area

ScanTech Dallas – Fort Worth EMF, Indoor Air Quality & Radon Testing Service Areas

www.emfinspectordallas.com

Dirty Electricity – Is it really “Electropollution” or a Real Threat to Health and Safety? The Dirtier Truth

Comparison of a "Clean" Powerline Signal (top) with one that has EMI or High Frequency Noise (bottom)

Comparison of a “Clean” Powerline Signal (top) with one that has EMI or High Frequency Noise (bottom)

“Dirty electricity” is a rather unscientific term used loosely to describe a signal waveform that has extraneous noise components riding on top of it – typically of higher frequencies and/or a transient random nature.

It is more accurate to describe it as a noisy signal or more specifically as 120 Volt 60 Hz AC with high frequency components. Incidentally, ScanTech Consulting has the capability to evaluate the amount of high frequency noise on a power line in the ranges of 10 KHz – 10 MHz in order to diagnose possible EMI and equipment interference issues. (see picture below)

The controversy is whether or not this phenomena has any measurable impact on human health and safety. Please notice that the use of the terms “dirty” and “electropollution”  have a negative connotation and will tend to immediately bias any reader. Also, the term “dirty electricity” and “electropollution” are not the same. Dirty electricity is any electromagnetic waveform that has unwanted and / or noticeable harmonics and regular or intermittent transients in either the voltage and / or the current component. Electropollution is another relatively unscientific term used by certain EMF consultants / specialists to describe potentially any and all electromagnetic waves of artificial origin, so dirty electricity is only a small subset of EMFs that could be included in the meaning of electropollution.

Bear in mind that there are a number of natural sources of electromagnetic noise such as the Schumann resonances, (spectral peaks in the Earth’s natural ELF field) and radio atmospheric signals which are known as “whistlers” and “sferics” (or also spelled “spherics”) which are produced by global lightning strikes that interact with the ionosphere and Earth’s magnetosphere.

Now before you think that I am completely dismissing the topic out of hand, I can tell you as an electrical engineering graduate that extraneous noise usually is a real problem, but it is normally far more so to equipment (particularly sensitive electronics) directly powered by it rather than to human health. I do have equipment designed to track this down, but this applies more to the commercial arena where (for example) anomalous equipment operation can be caused by a nearby defective (or poorly filtered) LED bulb or an arcing motor in some other part of the building.

Most power supplies are designed to filter out and/or minimize the potential damage that these noise spikes and transients can do before they reach the vulnerable logic components of your computer or charging cell phone. In addition, surge suppressors and UPS (uninterruptible power supplies) are an inline solution to prevent some of the larger transients such as those from a nearby lightning strike from doing something unpleasant such as zapping the motherboard of your PC.

Actual Scientific Measurement of High Frequency Electrical Noise on an AC Powerline

Actual Scientific Measurement of High Frequency Electrical Noise on an AC Powerline

They are also designed to filter out noise that may corrupt data such as on an Internet LAN cable or in critical medical and scientific equipment such as an EKG monitor or scanning electron microscope. But on occasion due to ground loops or incompatible equipment grouping, even the best power supplies can be thwarted if the data/signal lines themselves have corrupted information and / or spurious noise. In this case, you are looking for what is known as S/N or the signal to noise ratio.

So what about the effects to human beings? Does the electric noise on your 60 Hz AC mains actually cause any health problems?

I find it unlikely for several reasons. For one, the overall amplitude of the noise is typically much lower than that of the 120 V AC already on the lines – usually by an one to two orders of magnitude. (at least 10 – 100 times less) Then assuming you are not directly connected to the line (which would be a far more dangerous and immediate problem than any alleged long term health effects) you have to consider the electric near field that is present near any energized line with voltage.

The electric field “couples” or induces voltages in the human body with very poor energy transfer because the very high dielectric constant of water present in the body shields the internal tissues, cells and organs. The resulting induced internal voltages and current in the body from external fields are reduced by an order of 1,000,000 times less.

So even with an external electric field of 1000 Volts / per meter (V/m) the induced voltages inside a human would be on the order of 0.010 V/m (10 milliVolts) or less. This is much less than the typical voltages generated within the heart and brain which are from 1 – 10 V/m. Furthermore, the endogenous DC fields generated by the flow of ionic current through cells in the body is on the order of 10 – 100 V/m.

I find it hard to believe that a 10 milliVolt field could substantially perturb a system that routinely generates voltages that are 100 – 10000 times greater. Again, this is within a 1 KILOVOLT / per meter electric field which is much higher than you will see anywhere except inside of an industrial electric room or underneath a high tension line.

The electric field generated by the alleged dirty electricity has a greatly diminished amplitude – probably no more than 10 V/m. Divide that by the same attenuating factor of 10^6 (1 million) and you wind up with induced voltages of 0.0001 V/m which is in the microvolt range.  (100 microVolts) This is even more unlikely to cause any noticeable change inside the human body given the fact that the resting membrane potentials of most human cells range range from -40 to -80 millivolts which is at least 400 X to 800 X greater than the 100 microVolts cited. The negative numbers for the internal voltages of cells are stated as such because you are measuring the voltage with respect to the ECF (Extracellular Fluid) surrounding cells which is used as a ground reference.

And again, this is in a 1 kiloVolt / meter field. What you encounter routinely inside of a home is at most 100 V / meter or so, and more typically 1-10  V /m. So divide that 100 microVolts by 10, 100, and 1000 and you wind up with 0.1 – 10 uV (microVolts) being induced in the body which is hardly a drop in the bucket as far as electrochemical signaling in the body is concerned. There is probably a greater pathological effect from listening to Barney The Dinosaur than this minuscule amount of “dirty energy” injected into a human host.

Even if there are minor effects, the body is an organism with a renowned impetus and ability to maintain equilibrium under a range of conditions. This is why we usually don’t perish as soon as something affects our blood pH, body temperature, glucose levels, etc. Our bodies are constantly keeping up with an influx of stress, bad food, bacteria, substandard air and food quality and a plethora of other threats and chemical / genotoxic insults. We only become ill when a substantial imbalance develops that our system cannot compensate adequately for.

In addition, many of us already have DSL for high speed Internet access which runs routinely pulses high frequency signals through telephone lines and yet I never hear any fuss or concern expressed over this medium. Granted, the practice of using twisted pair conductors does prevent this “noise” from radiating any appreciable distance, but it is in the high frequency ranges that many claim are damaging when present on a power line. I find it interesting that certain so called “experts” seem to cherry pick what type of noise is clean or dirty.

At any rate, I do not claim that electromagnetic energy is COMPLETELY harmless, only that it is better to calmly examine actual data and put said risks into proper perspective.

But whether you are interested in “cleaning up dirty electricity” for either the benefit of your electronic equipment or because you are concerned about the safety risks to your health – I would strongly advise that you read this article concerning devices that claim to eliminate electrical noise / health risks and what the real effects are:

EMF – Harmonics, and questionable means to “clean” them

This is your friendly Dallas / Fort Worth / Houston / Austin EMF Testing Inspector signing off for now.

Stay Well!

SCANTECH EMF CONSULTING  214.912.4691

Typical EMF & RF Sources in the Home

Homes have several potential sources for high EMF and RF sources including:

  •  External high voltage power lines (both primary and secondary feeders) which can produce elevated levels – particularly in densely populated urban areas / cities such as Dallas, Fort Worth, Houston, Austin, etc. or in homes near utility easements
  •  The main 120/240 volt feed entering the home through the power drop
  •  Breaker boxes
  •  Fluorescent lights (some also have an RF component as well which can cause equipment interference)
  •  High output halogen lamp banks such as those used in track lighting (uses a lot of current)
  •  Appliances with motors or heating elements (washers, dryers, refrigerators, etc.)
  •  AC Adapters
  •  Wiring Errors
  •  Outside Air Conditioning Compressors and Pool Equipment
  •  Wireless Routers, Cell Phones, Bluetooth and Cordless Phones (radio frequency only)
  •  Smart Meters (but fairly low level)
  •  Dimmers (though the range tends to be very short, but I have seen them wreak havoc with sensitive electronic equipment)

The focus should primarily be in areas exposed to EMFs where occupants spend 90 % of their time or greater – this sample schematic gives examples.

Focusing on areas where people spend 90% of their time

Focusing on areas where people spend 90% of their time

LFE means Low Frequency Electromagnetic – this is the typical ELF (Extremely Low Frequency) band for 60 Hz AC power

Typical Low Frequency 60 Hz EMF

Typical Low Frequency 60 Hz EMF Sources

Higher frequency RF sources in the home including wireless routers, printers, laptops and other portable cell phone / tablet devices – DECT means Digital Enhanced Cordless Telecommunications

Typical High Frequency RF Sources in the Home

Typical High Frequency RF Sources in the Home