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Where do I begin?![]() If you are the type of person who likes to know everything about a subject before you begin your journey, you have a long road ahead of you. Here is some practical advice for the beginner that will help you get started immediately, and lead you towards effective solutions right away.
1. Diagnose your EMF exposurePlease don't call and ask us how much exposure you are getting from your TV, toaster, iPad or any other device. We cannot know the answer to this question. First of all, you will find that emissions vary from model to model, that they vary with distance, and that they vary over time (Is the device plugged in? Is it turned on? Is it running? Is it on the high setting? Is it charging? Etc. etc.) In addition, your total exposure is the sum of exposure from ALL sources in your vicinity. It is possible that the majority of your exposure is coming from a source different from what you think it is (Is the refrigerator next to the toaster? Is there wiring under the floor that you don't know about? Is there a TV on the opposite side of the wall? Etc, etc.) You must determine your exposure with a meter. Period. Get a meter and begin by making measurements where the people are. It doesn't matter if there are high levels where there are no people. Check your bed, your couch, your car, your kitchen. Check the areas where you spend time. And take your meter with you throughout the day to make measurements while you are actually doing your activities. (There could be a big difference between day versus night levels in your bedroom, in your kitchen when the stove is on versus the microwave, or in your bathroom when the fan, hairdryer or heat lamp is on.)
If you find high levels where the people are, the only next step is to determine the source(s) for these high levels. Use your meter to sweep the area, sweep the walls, floor, ceiling and the objects in the room. As you get closer to the source, the EMF levels will increase. If necessary, unplug or use switches and circuit breakers to turn on/off certain things to see if that is where the trouble originates.
2. Mitigate the worst situation firstOnce you have determined the sources of EMF in your environment, pick one... usually the worst one... to take care of first. It's tempting to start with the easiest problem, but common sense and experience tells us to start with the worst problem first. Then move on to the next most urgent problem. Most importantly, take SOME action. For any given source, consider all of the following:
Use distance to reduce exposure
Get rid of EMF sources
Install shielding
Why do the readings on two different RF meters not match?
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: a) What is the specified time? Different sample times will yield different results. b) Is the meter reporting peak or average? Some meters do not specify. c) Is the meter reporting some combination of peak and average?
6] SensitivityEvery 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. What is the real difference between a single axis and a triple axis gaussmeter?
I am already EMF sensitive and I know what bothers me...
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Finally, a meter will stand guard to changes in your environment and alert you before you become ill. Did a new cell tower go up? Was a smart meter installed? Did your neighbor get a new wi-fi device? Did your church install a new wireless microphone system? Using your sensitivity as your only guide is like using your stomach as to learn if your food is poisoned. By the time you know your have a problem, it's already too late... the exposure and its damag have happened. If you are electrically sensitive, you must have an EMF meter. Your health depends on it. |
Whether is it electric fields, magnetic fields, or radiowaves, the source of the field will always be in the direction of the strongest signal. It is critically important to avoid being fooled by thinking that the meter points in the direction of the source.
A perfect example of this phenomenon involves powerlines. You should remember that the direction of magnetic field lines around a current carrying wire is circularly perpendicular to the wire. So alongside the wire, the field lines are vertical, while underneath the wire, the field lines are horizontal. The proper orientation of a single axis meter may point the meter at the wire, or straight up and down, or even horizontal, depending on the orientation of the sensor in the meter and the position of the meter relative to the wire. Furthermore, the orientation of a 3-axis meter is irrelevant to the reading, so it could be pointing in virtually any direction and still give a correct reading.
Only by moving the meter bodily toward, then away, from a suspected source can one determine the location of the source. Just like the "Getting warmer.. getting colder" game, the meter will indicate if you are moving into an area with higher field strength (closer to the source) or lower field strength (moving away from the source).
There is much concern about the health effects resulting from microwave radiation from cell tower and radio antennas. Biological effects have been clearly established at levels well below the government exposure limits.
However, people are often surprised to learn that the strength of the signal from a cell tower or radio antenna is extremely small if you are any distance at all from the antenna. At 100 yards, the signal strength is well below the sensitivity of most meters. In order to measure these signals, you need an extremely sensitive meter. You also need a meter which can accurately process a digital signal (which is different from an analog signal in the way it interacts with a meter), and it would be useful to have a meter which is directional, so that you can take a measurement of a specific tower, without interference from extraneous sources behind or to the side of you.
For these reasons, there is only one best meter we recommend for measuring antenna: HIGH FREQUENCY METER. It has the sensitivity (10 picoWatts/cm²) to measure an antenna miles away, process analog or digital signals correctly, and it'S antenna is directional.
The 3-axis RF Meter is probably the best pick for non-technical users. It is very easy to use, very sensitive ( down to 0.4 nanoWatt/cm²) and gives a calibrated, digital readout of field strength.
This is perhaps the trickiest measurement you are likely to attempt. The reasons include:
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. But what can an ordinary person use to measure the output from his phone or check the effectiveness of a shield?
We recommend the 6 GHz RF Meter with Near Field Probe accessory. For about $240, you can use this NEAR FIELD meter to check all surfaces of your phone and establish where the hot spots are.
When measuring distance, you can use a variety of units: inches, centimeters, miles, fathoms, etc. Some units are larger than others. Some are more familiar than others. However, regardless of the units you use, the distance you measured remains constant but the number you get can vary widely.
Similarly, when measuring radiofrequency signal strength, many different units can be used. They are all equally valid*, and you can convert from one unit to another. But some units are much bigger than others.
You wouldn't measure the distance from Paris to Rome in inches; you would use a bigger unit... perhaps kilometers. Likewise, you would use a very small unit to measure the thickness of a human hair. So, when measuring the generally low levels of background RF radiation, you can use a small unit, such as V/m. When measuring the relatively large amount of radiation that leaks from a microwave oven, you can use a larger unit, such as mW/cm2.
The image shows the relative size of some units compared to 1 V/m. Notice that A/m is a much larger unit, almost 400 times the size of one V/m. A/m is better suited for measuring very strong radiation.
* Engineers will have a preference for one unit over another, particularly when measuring in the near field.
Units of field and power can be converted. Use the formulae at the right for radiofrequency conversions. Below are some additional conversion equations:
Nice table of conversion units
Unit conversion applet
This is a very tough question to answer. Harassment could take many forms: chemicals, ions, sound, microwaves (what frequency?), light, covert technologies, and so on. There is no one meter that can measure all these different phenomena. Furthermore, your symptoms may be due to something else altogether such as allergies, migraines, high blood pressure, or a thousand other conditions.
If you are serious about determining if you are being intentionally exposed to electromagnetic fields, then the logical place to start is with meters which offer the widest range of sensitivity.
One possibility is the combination of the Trifield TF2 Meter plus the AC/DC Milligaussmeter will cover a huge range from DC to 10 KHz, then from 20 MHz to 6GHz. This combination offers the ability to distinguish if the offending field is AC or DC, and whether it is electric, magnetic or microwave.
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.
So 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:
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.
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