Flux Health Forum

Intensity of C5 model

Sorry to ask so basic question here but I could not find info on the site.

C5 has several levels of intensity. If we take the minimal 1st level - what’s the number in mT (Gauss)?

Depends on where in space you measure it, what the physical configuration of the coils is… It’s really the wrong technical question to ask honestly. But what you will find hundreds (thousands??) of times in all of my writings is the explanation as to why this is the wrong question to ask.

I have read your main article on PEMF and watched the video but I somehow missed this discussion. Would be grateful if you send a link here.

I believe that all manufacturers provide figures for the surface of the coils and for most popular and standard coil configuration

From my point of view it’s important to understand to which category the device belongs. There are devices working primarily:

  • in Tesla range
  • in mTesla range
  • in microTesla range
  • in nanoTesla range
  • and even in picoTesla range (though this an exotic)

Concrete figures may be misleading but at least a degree shall be given.

Am I wrong?

They do that, but when tested independently, it is widely known among PEMF developers/manufacturers that these numbers are very often over-stated by a factor of 10x to 100x. So, the published information (which are nothing more than advertisements, since people think they are buying PEMF by the Gauss) can not be accurately used for comparison. Comparing PEMF products by their published Gauss is like comparing automobiles by the setting on the radio. Sure, you can do this, but really, it is irrelevant. And I explain this, many, many, many times.

Most of the figures given by PEMF marketers are, in fact, are intentionally misleading.

With all that being said, under standard testing conditions, which I had to establish for our products for manufacturing process control and calibration, yields reliable numbers.

Since I have been asked this same question, the wrong question, thousands of times, here it is again:

First, find the BIOLOGICALLY MEANINGFUL AND RELEVANT numbers on pages 11 and 12 of the comparison document, which shows the magnetic field generation for all four current ICES-PEMF products:

This has been posted publicly and has been readily available for several years.

But this is not the number you are asking for (Gauss), it is kG/s, the correct, physically and biologically meaningful units.

To get the number you want, you would need to multiply that number by the pulse width (100 microseconds, or 0.0001 second)

For example, the standard peak Gauss measurement (1,700 kG/s) is achieved in 0.0001 seconds. This means that the peak Gauss level will be 170 Gauss. Gauss can be converted to Tesla: 1 Tesla = 10,000 Gauss

But, this is the wrong number to use for comparisons with any other product, unless
(1) all testing conditions are known to be identical (they are not),
(2) the pulse shape and duration is identical (they are definitely not),
(3) the measurements are taken correctly (most PEMF marketers never actually measure the real performance of their device because it is difficult and expensive to do: it is just easier to make something up),
(4) the assumption that it will be reported accurately (it is known that this is frequently not the case)

I think that is the number you want, but it is absolutely irrelevant and incorrect to use it in comparison to other PEMF systems that function differently. The correct number to ask for has units of kG/s, but not a single PEMF manufacturer that I know of, last time I looked, actually knows, understands, measures, or reports this biolophysically critical value.

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Thanks Bob, but this is not the question which I asked :))

I asked the question which is the minimal intensity.

The device has 15 levels. If they are linear then the minimal intensity is 1/15*170 Gauss =~ 10 Gauss = 1 mTesla. But are they linear?

That actually is a more interesting question. Thank you for correcting me on that point.

There is a minimal Gauss that would be expected to work, but this too can be tricky.

First (before I get too carried away): the relationship between the settings on the C5 (or B5) and the peak Gauss are linear with an offset (non-zero). So, by the technical definition of linearity as it relates to scientific instruments, they are not linear, only because the line that relates them does not have a zero intercept. Otherwise, the relationship between the intensity setting and the resulting Gauss (under standard test conditions) is linear. This is actually true for all of our devices: C5, B5, M1, and A9.

On the A9, HIGH corresponds to about 160 Gauss peak, whereas LOW = 70 Gauss peak. On the M1, C5, B5, the highest setting (15) corresponds to about 170 Gauss peak, but the lowest settings correspond to lower than 70 Gauss, about half of that, but it becomes increasingly non-linear as the power settings are reduced due to the peculiarities of DC-to-DC conversion electronics at low gain and low intermittent load. So, it would be safe to say that at the lowest settings, the C5/B5/M1 are generating only about 30 Gauss peak.

Now, be sure to understand that this is not a good number to use for, well, anything. It has been so thoroughly distorted, miscommunicated, and abused by PEMF marketers for the past two decades that you should not rely on it for any comparison. But when looking at minimum Gauss, it is possible to infer some meaning when you grind through the math.

Basically, the peak Gauss for a biophysically meaningful PEMF signal will be a product of two factors:

(1) The pulse has a minimum threshold dB/dt (slope of Gauss versus time). This must be determined experimentally.

(2) The pulse has a minimum pulse width, determined to be as a minimum ~ 80 microseconds. So, ICES-PEMF devices are all set to 100 micro-second pulse width.

Based on threshold experiments, where we observed the minimum magnetic slope required to elicit a biological response:

(see figure 22.4: dose-response)

and also see:

We found a minimum threshold around 700 KG/s, corresponding to a peak magnetic pulse of 70 Gauss for 100 microsecond pulses, but depending on the biological effect you are looking for, this threshold can vary quite a bit, from about 400 to about 800 KG/s (corresponding to 40 to 80 Gauss peak for 100 microsecond pulses).

But there did also seem to be species-specific differences in sensitivity. Horses, for example, seem to be much more responsive to PEMF than humans, dogs, cats, or rats. This was anecdotal, but was observed repeatedly by different individuals. Also, in the initial studies done at NASA:



In these, the peak Gauss level was very low, but the rate of the rise and fall of the magnetic field was very large, and the studies were looking at a very sensitive biomarker: gene expression in neuronal cells in culture.

So, under some circumstances you may be able to detect significant biological effects with very low peak Gauss levels. On the other hand, when looking at organismal-level responses in animals that respond similarly to humans, the lower limit does seem to be around 400 KG/s (40 Gauss peak), because the pulse does need to be active for about 100 microseconds, and in the final analysis: peak = rate X time.

The key take away message is this: it is the rate and the time that are important, but the peak (Gauss) is simply the product of the two. Thus, “Gauss” is not fundamental to the biological effectiveness of PEMF, it is a byproduct.

Taking all of this together, I would say the lower limit for a functioning PEMF device, if everything else is designed properly, might be about 40 Gauss peak field strength for each magnetic pulse. I made sure to set the minimum intensity values for the C5/B5/M1 to levels somewhat below this because some people and some animals are somewhat more sensitive than others. The maximum values for the C5/B5/M1 are set to slightly above the point where we see a leveling-off of biological effects.

Hi Bob, thanks for your very interesting answer

I know that you don’t position your devices for sleep assistance or for brainwave entrainment. However, some of your clients do use your devices for these purposes.

I would suppose that for these purposes 100 mGauss intensity from the report which you provide the link to - and where you say the peak Gauss level was very low - may not be so low.

Natural Earth field has the intensity of ~40 microTesla while it’s strongest impulses are 0.1 microTesla. Unforunately I don’t know the speed of intensity change.

I would suppose that for sleep the parameters just slightly higher than natural Earth field would suffice. I.e. the intensity level of 0.1 to 1 microTesla is enough (if we measure it on the scalp).

Yes, the modern Neorhythm device has 2 milliTesla on the scalp but it might be too much especially for frequent use.

Then your 30 gauss = 3 mlTesla may be even a bit high. Certainly people put the coils under a pillow for sleep assistance so the resulting field might be 10-100 times less intense (this is just a guess - I don’t know how to calculate and certainly it depends on the thickness of the pillow)

Just thoughts

Well, I know very little about sleep. I may know a lot more about it than many people who market devices for sleep, and sometimes it definitely seems to be that way, but I maintain that I know very little about sleep, so I offer no advice as I have no expertise or direct personal experience with sleep problems. But I do know for a fact that several PEMF marketing firms have blog/SEO/forum-puppet farms in India and China that will be happy to tell you anything you need to hear about PEMF and sleep, so long as it triggers a purchase. The only job requirement is that they speak/write convincingly in English. I know about these because I get offers from them all the time to support the sales of our products, and they sometimes say things like “we also support…”, or “we generated $X in sales for …”
So, yes, there is a lot of “expertise” out there for the use of PEMF with sleep.

I just stick with the fields I know, and sometimes I have to tell people things they do not want to hear. One of those things, unfortunately, is that very, very little reliable information is actually known about the use of PEMF to enhance sleep.

I can tell you, anecdotally, that the brain does seem to be more sensitive than other tissues, which makes sense as it is composed largely of nerve tissue. And I can tell you that the combined effects of brainwave entrainment plus the other immunomodulatory/anti-inflammatory effects of PEMF are brought together when using PEMF on the brain/CNS. But honestly, people respond very, very differently. I have been at scientific/medical conferences and seen people with hundreds or thousands of hours of experience using PEMF on themselves and their patients argue among themselves, taking up the full spectrum of possible positions:

  • “Only Delta Wave frequencies enhance sleep”
  • “No, only Theta-wave frequencies enhance sleep”
  • “No, only [insert you preference here] waves enhance sleep”
  • “No, I have never seen any beneficial effect of PEMF on sleep”
  • “No, what I see is that every waveform enhances sleep…”
  • And may of them argue about the intensity, the waveform shape, periodicity, correlation to points in the sleep cycle, placement of coils on the skull, etc.

Well, who is right? I suppose in a way they all are. It depends on their individual sensitivity, their conditions that are causing a sleep disturbance, and their precise conditions of use. I can see the strength of any argument or observation that I have heard when it relates to sleep.

ICES-PEMF was developed specifically to deal with severe, chronic, crippling idiopathic pain and inflammation. It seems to help with a lot of other things too, sleep being one of them, but I have very little to add to that conversation. So, I could not say, for example, how much intensity is too much, or too little, as it relates to sleep.

But you are correct: people have placed the device under a pillow, or even under a mattress, and reported to me that they had very good effects related to sleep. I just wish some of those people would sign on to this forum and discuss it openly.

Just FYI, since you mentioned that you do not know this for sure:
Magnetic fields drop off very quickly with distance, much faster than a beam of light, for example. A point source of light (a candle, for example) will drop off according to the inverse square law: double the distance, the intensity drops off 1/2^2 = 1/4. Therefore, double the distance, the light intensity drops to 1/4 of what it was when closer by a factor of 2.

But magnetic fields drop off much more quickly than this, and in a much more complex way because it depends on the presence of other magnets, the magnet orientation with respect to the point you are interested in, etc. Magnetic fields, very simply, drop of at a rate of 1/2^3 (a factor of 1/9 when doubling the distance), or 1/2^4 (a factor of 1/16 when doubling the distance).

This is real since, real complex and nuanced, and you can’t just pick it up by reading blogs. The best way to start to understand it is to grind through a few years of college-level physics. But the bottom line is that as an end-user, you really do not need to know the details of electro-magnetism, any more than you need a mastery of advanced thermodynamics to drive a car. But PEMF marketers abuse all of this, and make up things such as “whole-body” mats, then try to teach you faulty physics to lend credibility to their snake oil.

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Bob, thanks for your answer. Very interesting

  1. Correct me if I’m wrong but I could buy a device measuring magnetic field and check the value without knowing anything about the details of electro-magnetism.

Certainly such device which would measure in the level of microTesla would cost closer to 1,000$ :)) Still it’s possible

  1. May I ask if I understand correctly how your device works. My understanding is that it has quite big duty cycle, i.e. there is a short impulse (0.1 milliseconds) and then long time of silence. For example, for the frequency 10Hz - impulse 0.1 milliseconds and then 99 milliseconds of silence.

If yes - why these short impulses are important? To achieve high speed of intensity change? But I thought that you’re getting it by the shape of the signal.


Quick answers:

  1. Actually that will not work. The devices for measuring magnetic fields are typically slow. Think of it like a light meter, for measuring light in your room, for example. For a typical person, they want to know only: how much light? The meter integrates the light signal for a few seconds, then reports the average.

For scientific purposes, you would generally use a high-speed detector and an oscilloscope. This would show that the lights are not on continuously, they flash on and off 50 or 60 times per second. Although this is more accurate, it does not really tell the average person the simple answer they want to know.

This is the same for ICES-PEMF. Each magnetic pulse is only 100 microseconds (0.0001 seconds) long, so the magnetic detector has to be very fast, and the display has to show the waveform with micro-second timing accuracy. No simple magnetic field meter will do this. To measure the wave forms while designing this device, I had to build my own magnetic field detection system. The device you are thinking about ($1000) is still much too simple. Mine cost about ten times that amount, and I still had to build it myself.

  1. Why short pulses and long times between pulses?:
    This is a very long scientific topic. You can read about it in my published scientific papers. But briefly, it simply comes out from the math (some calculus):

Determine dB/dt (must be done experimentally)
determine minimum t (also done experimentally)

Multiply the two to get the resulting B

Determine the pulse repetition rate (has been done many times in the scientific literature, usually called “frequency”)

“t” is much shorter than “1/f”, and any field generated that is not at the threshold dB/dt has no biological effect, but does draw extra power and generate biologically ineffective magnetism. It also causes excess heating to the coils, and therefore for these reasons (and several other health and safety reasons) unneeded energy must be eliminated. That means: when the device is not changing the magnetic field at the appropriate rate (dB/dt), the output must be turned OFF.

Therefore, the device is only generating a waveform a very small percentage of the time “t” for every pulse interval “1/f”.

Your nerves are similar: they only transmit pulses a small percentage of the time.

There is no benefit to generating biologically ineffective electro-magnetic energy, but the technical drawbacks of doing so are very significant.

Like so many other things, when something is OFF is at least as important as when it is ON

To understand this, you basically need to understand the biology and biophysics of electro-magnetism. You would need to study quite a lot of papers and texts in many disciplines, and even then, the knowledge in the overall field of PEMF is incomplete.

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Bob, thanks, very clear

Bob, I have two questions. I have the C5 as well as the M1 and A9 devices. I use the C5 when I am laying down in an light based sauna. I usually have it running in the red and infared spectrum. While it is one that you lay in with head exposed to blowing cool air. I use the C5 on my pillow to enhance a meditative state. Since it has so many leads. I am curious if the output of the signal is per coil or per output it is plugged into. Does the coil output increase with fewer coils or are they all the same no matter how many I put in. As a side note I use the A9 at night for longer hours while sleeping. Is there any reason you designed the other two to run for only 1 hour at a time?
Thank you

All four outputs are independently powered, so their output power of each will remain unchanged no matter how many other coils you have plugged in.

I did not design any of our systems to run only for one hour, except one protocol, which is the sub threshold transcranial magnetic stimulation hold protocol specifically because the FDA-approved clinical equivalent of that protocol is defined to only run for one hour. But all other protocols will run for as long as you want them to, or until the battery runs out.

Thanks for that feedback. That happens to be the protocol I was running. I did not realize it was the application and not the device that was limiting the time frame. I will try some of the other protocols for longer duration.

There is a similar protocol that runs for only 30 minutes, so you want to avoid that one too. But all other protocols will run indefinitely.

Just got the c5 today and I’m excited to put this to good use!

are all coils set to run the same protocol at the same power level? i was considering using the c5 in this way:
one set for my head using Delta protocol side by side at 8 and another 2 sets using Omni sandwiching my pancreas stacked at 15 and a 2x2 set using Omni at 15 for my shoulder

The C5 and B5 run all the same protocol (whatever you set it to) at all the same intensity (whatever you set it to). This allows them to be synchronized, so they can be used together, stacked with additive intensity, etc.

Hi @Bob

Thanks for clarifying the Tesla/Gaus issue. Helped my a lot to better grasp the issue.

From B.E. Meyers I remember: EMF = – ΔΦB/Δt, but that includes surface. As I understand Meyers is the Wb/s proponent. Its the argument to sell “large” coils that potentially can penetrate deeply, too.

You state its more T/s (or G/s) that is relevant. I like your reasoning, because it is the energy-“Flow” per point and not so much the summ of the energy-“Flux” over a surface (in Weber, Wb).

Q: Is my thinking correct?


well, your thinking is probably correct when conceptualizing point versus surface (or surface integral) effects. That’s my interpretation anyway. But, this opens the can of worms for almost everyone else, people who do not have a solid command of physical units. People will start asking questions like “Wait, I thought it was Gauss, now what’s this Weber thing?!?”

Overall I think this just demonstrates the complexity of the physical units for describing magnetism, combined with our lack of scientific knowledge of how magnetism influences biological processes, and how biological processes are modulated by spatial and temporal gradients of magnetic fields, and crucially, whether the effect of magnetism is one of bulk energy transfer, or molecular-scale information (signals).

I was about to spend all day writing another 6000 word essay on this, but since I have already done this many times and they all converge on the same answer that I think is the best answer that I can give based on a quarter century of studying and developing PEMF, I will be brief:

1- If someone is selling “Gauss”, there is a good chance that they do not know what they are selling (and they totally miss the energy vs. signal nuance).

2- More power is not necessarily better (a cornerstone of the “bulk energy” argument).

3- Changing magnetic fields induce electric fields in tissues, no matter what physical units you use to measure them: G/s, T/s, (Wb/m^2)/s, whatever. (basic physics)

4- The argument to use large coils versus small coils brings in all of the complexity and lack of complete understanding of biological gradients. (a dys-conflation of energy versus signal, missing the main concepts and just mucking it all up)

5- The current state of scientific knowledge does not allow us to calculate the “best” form of PEMF for optimal biological effects. So, we are left with doing the best we can with our current understanding of the biophysics plus a lot of experimentation, trial, and error. (limits of knowledge)

6- Unfortunately #5 leaves a lot of room for pseudo-scientific fraud. (market fact)


Beware of charlatans selling high-power Gauss, and use whatever PEMF works for you, regardless of the differential equations.

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Hi @Bob

Thanks for your answer. You are probably right with the understanding of the physical units. I have a formal electrical engineering and electronics education + an informatics degree and lots of industry experience - so that helps me a bit. Still, I have to come up with a 3d-picture in my mind of how things work. That is limiting.

Regarding the biology, I agree that we do not know much. Lots is electron flows, reduction, oxidation, transformation inside the body - without we are dead. Voltage-Gated Ca-Channels have kind of an “Antenna”, that makes them susceptible to EMF. Dr. Martin Pall things that is a reason how “bad” EMF work. Then we have the metals inside protein complexes. Moving a load there could change the stereo-chemistry of a enzyme-complex and activate or deactivate an enzyme. This is hypothetically shown for the Vitamin D Receptor (VDR). Its pity that the research in this topic is so limited. Then we have multiple ways of communication inside the body… coherent light, miRNA, Exosomes, different ways to drive gen-transcription and expression / production of enzymes and protein complexes…

Regarding the power-issue I agree with you as an EMF sensitive person. I liked you picturesque description of the amplifier. More power does noch necessarily make the music or message better understandable.

So if you have done your 6000 words, please tell us :slight_smile: