March 17

What Are EMF Meters and Does Every Household Need One?


What exactly is EMF Radiation, and why is long-term exposure a problem? And if EMF exposure is a problem, how does one see for themselves the size of the problem that EMF Radiation exposure is in one’s own daily routine?

The second question above is where we enter into the meter conversation. Meters for various sections of the EMF spectrum measure the strength of the EMF at a particular spot, at a particular point in time. Given that reality, we also need to understand why different meters give different reading at essentially the same spot, at essentially the same time.

In fact, the same meter may give a different reading at the same location, at the same time, if one changes the orientation of the meter. So, why then do I even need a meter or is it is just going to confuse me?

Let us start with a short refresh on what exactly EMF is – Electromagnetic Field (EMF)

Electromagnetic Field (EMF) Radiation Spectrum

EMF radiation can be classified from very low frequency (long wavelength) to very high frequency (short wavelength) as show below.

Graph of the electromagnetic spectrum

There are 4 basic parameters involved with any EMF exposure that combine to give a more accurate picture of what the potential danger of that exposure are:

  • Frequency: The higher frequency an EMF is, the more energy it carries and the more likely it is to be dangerous.
  • Power Density: The average energy of the electromagnetic waves in a given area or volume.
  • Strength: of the electric and magnetic fields that are present.
  • Duration of exposure: prolonged duration is usually worse than acute duration for the same levels of EMF.

The World Health Organization established a guideline for safe EMF exposure, while different countries also have established their own guidelines. According to a report by Netherland’s National Institutes of Public Health and another report by Dr. Jack Kruse, Russia has the strictest requirements while the US allows for more EMF exposure.

In fact, if you go the US government site which is in charge of managing such things, you will see that the guidelines have not been changes since they were established in 1999.

The National Institute of Environmental Health Sciences categorized EMFs into two different groups, i.e.

  1. Low frequency EMF radiation. They have lower frequencies than visible light and are non-ionizing radiation. Examples include EMFs from microwave ovens, computers, visible light, smart meters, Wi-Fi, cell phones, Bluetooth, power lines, and MRIs.
  2. High frequency EMF radiation. These have higher frequencies than visible light, which are ionizing radiation. Examples include ultraviolet (UV) light, X-Rays, and Gamma rays.

So, if we have guidelines, and the guidelines are followed, why do we need to worry? The answer is of course that this is a very complex subject, and on one hand the Businesses creating and selling equipment that produce EMF emissions have a financial interest in not having any liability for health problems that might be associated with their products.

This definitely includes the cell phone industry, which is currently rolling out 5G, the better/faster /stronger, wonderfully improved next generation!

On the other hand, we have the scientific and medical folks who are seldom if ever consulted on the safety of new technology. The other factor here is that EMF exposure doesn’t always cause immediate problems, but is more of a problem with prolonged exposure, and even then the effects may come on gradually.

Below are some examples of “Field Experts” and their concerns:

Magda Havas, PhD

Associate Professor, Environment & Resource Studies, Trent University, Canada.

Expert in radiofrequency radiation, electromagnetic fields, dirty electricity and ground current.

Radio frequency radiation and other forms of electromagnetic pollution are harmful at orders of magnitude well below existing guidelines. Science is one of the tools society uses to decide health policy. In the case of telecommunications equipment, such as cell phones, wireless networks, cell phone antennas, PDAs, and portable phones, the science is being ignored. Current guidelines urgently need to be re-examined by government and reduced to reflect the state of the science. There is an emerging public health crisis at hand and time is of the essence.

Eric Braverman, MD

Brain researcher, Author of The Edge Effect, and Director of Path Medical in New York City and The PATH Foundation. Expert in the brain’s global impact on illness and health.

There is no question EMFs have a major effect on neurological functioning. They slow our brain waves and affect our long-term mental clarity. We should minimize exposures as much as possible to optimize neurotransmitter levels and prevent deterioration of health.

Samuel Milham MD, MPH

Medical epidemiologist in occupational epidemiology.

First scientist to report increased leukemia and other cancers in electrical workers and to demonstrate that the childhood age peak in leukemia emerged in conjunction with the spread of residential electrification.

Very recently, new research is suggesting that nearly all the human plagues which emerged in the twentieth century, like common acute lymphoblastic leukemia in children, female breast cancer, malignant melanoma and asthma, can be tied to some facet of our use of electricity. There is an urgent need for governments and individuals to take steps to minimize community and personal EMF exposures.

Back to EMF Meters

After going through the information about EMF, like me, you may be wondering if perhaps we should be actively doing something to protest ourselves from EMF exposure. And once again, I ask myself, how do I determine just how much of a problem there is in my personal environment? So, I come back to meters, to help me understand where I am, and if I implement changes, how much has that helped?

The first step is to understand that there are different types of EMF meters. Each type measures different things, so of course if I want a full picture of my EMF exposure, I may need more than one meter.

Or, perhaps I can get some idea of my exposure with one and guess?

Review of EMF Meter Types

  • • Low frequency EMF (from the presence of electricity): Trifield Meter, Digital Combination meter
  • High frequency (radiowaves, microwaves, wireless signals): High frequency meter, 3 Axis RF meter
  • Dirty electricity (high frequency signals on the wiring): Stetzerizer meter, Line noise meter
  • Body Voltage (voltage induced in the body from exposure to EMF): Body Voltage meter

There are several reasons why two different models of RF meter will give a different reading. In the real world, it is rare to encounter a single signal. Generally, a wide mixture of signals from multiple sources will be present. These signals will have different frequencies, different orientations, and different digital characteristics. How a meter interprets these differing aspects will impact the readout.

1. Frequency Range

Every meter has a specified frequency range. 30 MHz to 2.5 GHz, for example. The meter can be expected to detect and report signals within that range. Signals which are outside of that range may be detected only weakly, or not at all. So if a signal is present which is within the range meter “A”, and outside the range of meter “B”, it will only show up on meter “A”.

2. Frequency Response

The size and shape of an antenna will influence how well it receives a signal of any given frequency. For every antenna, there will be frequencies that it picks up better than others even within the specified frequency range of the meter.

Imagine listening to a marching band. If your hearing is better for the high notes of the piccolo, or the low notes of the tuba, your experience of the same performance will be different than that of the person standing next to you.

3. Same Time and Place
If you have taken RF readings, you know that the levels can fluctuate widely from one moment to the next and from one location to the next. Even moving the meter a few inches to one side or another can have a large impact. It is difficult to place two meters in the same location at the same moment, so part of the difference in readings is due to this time and location difference.

4. Orientation of the signal
All RF signals have an orientation in space. They may be vertically or horizontally polarized, they may be circularly polarized. The orientation of the meter’s antenna relative to the signal will greatly impact the meter’s ability to “see” the signal. If the antenna is aligned properly, it will see the signal. If it is not, the readout will be lower . When multiple signals are present (with different orientations), it is difficult to define the “proper” antenna orientation.

In addition, signals may be originating from different locations. So, for example, one signal may be coming from the North, another from the East. The direction that the meter is pointed will impact how well the meter “sees” a given signal. If pointed to the North, it will see that signal very well, but could miss the signal from the East entirely.

Further, it is possible that the user’s body may partially shield a signal coming from behind, reducing the meter’s ability to detect it. Also, objects nearby may be reflecting some signals, so that not only is the primary signal reaching the meter, but signals reflected from nearby objects could increase the amount of radiation reaching a given spot.

5. Peak vs. Average
Most signals today are digital. Digital signals are composed of a series of short bursts separated by periods of quiet, almost like a barcode. It is possible to define the strength of the signal by reporting the peak intensity (the strongest burst within a specified time) or the average intensity (the average of all peaks plus quiet periods within a specified time). This creates three possible discrepancies between different meters:

  1. What is the specified time? Different sample times will yield different results.
  2. Is the meter reporting peak or average? Some meters do not specify.
  3. Is the meter reporting some combination of peak and average?

6. Sensitivity
Every meter will have both an upper and lower limit of the strength of the signals it can measure. Some meters will be more sensitive than others on the low end, meaning they can detect weaker signals.

Taking all this together, it is a wonder we can measure RF signals at all! In truth, no meter detects all the signals which reach its location, for the reasons listed above. It comes down to how much of the signal present does the meter capture and how much does it not capture. As you can see, part of the answer depends on the characteristics of the meter, and part depends on the orientation and characteristics of the signal.

The main features to consider when choosing a meter are:
– Readout type: lights, sound, numbers, needle gauge
– Range: how sensitive on the low end, and the upper limit on the high end
– Axis: 1-axis only, 3-axis only, switchable 1-axis and 3-axis
– Accuracy: While high accuracy is desirable, it is not often necessary for locating “hot spots”
– Outputs: voltage output or PC interface for data logging
– Frequency weighting
– Other features: alarm, memory, and spectrum analysis

What do you want your EMF meter to do?

So, now that I know a little bit more about meters, what is it that will help me in daily life avoid EMF dangers? Let’s take a look at one specific case.

How Do I Measure the Radiation From My Cell Phone?

This is perhaps the trickiest measurement you are likely to attempt. The reasons include:

  • Because the phone is used directly against the head, the only valid measurement of cell phone radiation is close up to the phone. At cell phone frequencies, the NEAR FIELD is on the order of a few inches. Therefore, measuring the field accurately within about 2 inches of the phone requires a NEAR FIELD probe. Most low-cost meters are FAR FIELD meters.
  • Most cell phones today use digital signals. An analog meter may pick up some radiation, but it will never give a correct reading due to its inability to process the digital signal properly.

There are NEAR FIELD probes which can be connected to a spectrum analyzer for a cost of $30,000 or more. And of course, there are $100,000 SAR machines for doing SAR testing.

What can an ordinary person use to measure the output from his phone or check the effectiveness of a shield?

Obviously, I am not planning to spend over a hundred grand to see how much EMF I am absorbing from my phone. So, what else do I need to know to decide if I even need a meter?

At What Distance From a Field Source Can I Use a Meter?

(that is, what is the range in distance of a meter)?

All meters have a range of exactly zero feet. This means that all gaussmeters, electric field meters, RF/microwave meters, etc. can only measure the strength of the field AT THE LOCATION OF THE METER.

What distinguishes one meter from another is the sensitivity. In other words, what is the smallest field strength that the meter can detect? A gaussmeter with a sensitivity of 0.1 mG is more sensitive than a meter which can only detect down to 1.3 mG. While the meter which is more sensitive can be successfully used further away from the source of the field, it is still only measuring the field at the location of the meter.

The next question is: if you have a meter with a certain sensitivity, how far from a source of field is it useful? The answer to that depends on 3 factors:

  1. What is the strength of the field at the source?
  2. At what rate does the field decrease with distance (1/d, 1/d², 1/d³ etc.).
  3. What is the pattern of radiation from the source?

Note: A magnetic field is concentrated at the poles of a magnet. Some sources may have symmetrical field patterns, some may not.

Without knowing a great deal about the nature of the source, it is impossible to determine at what distance a given meter will begin to detect its field. What you can do is easily compare the minimum sensitivity of one meter to another. This specification is given in the description of most meters.

Conclusion – The Answer

So, now we have an approximate answer. For the average person it is practically impossible to get accurate EMF readings. Ok, so now I either give up, believe one side or the other and trust I have chosen the right side (Industry VS Health/Medicine). Or, I look around at the many products available that claim to help protect me, and somehow test a few to determine which to use.

I personally chose the latter. I purchased a Trifield TF2 multirange meter, purchased a variety of EMF protective devices, and started testing to see if I could detect any differences between before using the protection, and after.

I won’t go into details in this article, but I did see positive changes when using the protection product’s, I had purchased. They of course varied by manufacturer, but that is to be expected. And since different products claim to defend from different EMF effects, it also produces differences in testing.

Since this is an article focused on EMF Meters, you may be wondering why I chose the meter I did? I actually did quite a bit of research on meters, and this multirange meter was mentioned in almost every place I looked as being a decent all-around affordable tool.

If you are like us at EMF Alert, then you are concerned with EMF exposure. You also want real feedback on the various protective measures available, you may to decide as I did, to get a meter of some sort and take a closer look at the EMF world around you. Hopefully you walk away from this feeling more knowledgeable about EMF, and more ready to make a decision on how to proceed.




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