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Peak value or average value of EMF meter measurements?
January 8, 2017
4:15 pm
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xchcui
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Hi.

EMF meters are usually showing on there displays the AVERAGE power flux density(w/m2) of the RF frequencies(at high frequencies),while showing the PEAK field intensity(v/m)of the same RF signals(usually when there are burst signals). But when the EMF meter is measuring the low frequencies signals(AC 50/60hz)of electric fields intensity(v/m) or the magnetic flux density(gauss),Does it show the PEAK values or the AVERAGE values of them? And are the charts(which can be find around the web) that show the exposure limits recommendation parameters for that low frequencies emf(50/60hz magnetic flux density and electric intensity)refer to PEAK measured value or AVERAGE measured value?

Thanks in advance.

January 9, 2017
12:49 pm
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xchcui
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Anyone?

January 10, 2017
11:11 am
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xchcui
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Is this forum activeConfused

January 10, 2017
2:10 pm
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peter williamson
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Hi xchcui
Yes the forum is alive and well, although fairly quiet at present. I hope someone can answer your questions as the whole issue of measurement and units is one which could do with some clarification and consistency. Just to add one more complication into the melting pot – Prof Trevor Marshall has said that peak measurements can also be expressed in microwatts/m2. But most articles or papers (at least the abstracts) don’t state whether they are measuring peak or average. He prefers Dbm (yet another metric), but I’ve never seen a comprehensible conversion to other units.

January 10, 2017
3:32 pm
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xchcui
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Hi Peter Williamson.

peter williamson said
…But most articles or papers (at least the abstracts) don’t state whether they are measuring peak or average. He prefers Dbm (yet another metric), but I’ve never seen a comprehensible conversion to other units.  

Yes,that is the reason why i opened that thread.I was browsing in the web,while i saw a lot of sites with exposure limits EMF recommondation parameters(include your site),but none of them(include this site)mentioned if the parameter are peak or avarage.
For example,on your site at that address:
https://www.electricsense.com/5…..radiation/
you,also,gave safe limits for the three type of EMF,but haven’t say if they are PEAK value
or AVERAGE value.May you refer to your charts on that address?

January 10, 2017
3:50 pm
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peter williamson
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Hi xchcui,
Just to clarify, I am not responsible for the content of this site – that is Lloyd Burrell’s responsibility. But I agree with your comments. The same applies to the Building Biology guidelines, which surprises me. I’ve never even seen a discussion of these metrics for power frequency EMFs, which is also surprising now you mention it.

January 10, 2017
7:42 pm
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xchcui
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Hi Peter Williamson.
Ok.I understand.
But since the charts that i attached are,still,related to the”electricsense”site,may you find the answer about them?
I had been trying to find an answer by myself,but so far with no success.
Since you have more option from me to find an answer to that question,
I will very appreciate if you may check the issue.

Thanks.

January 14, 2017
12:09 pm
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peter williamson
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A little digging has revealed:

Measurement

Gigahertz meters seem to use RMS for power frequencies. Probably fair enough as they should be continuous rather than pulsed.
https://www.gigahertz-solution…..20/me3030b – see Technical Data

I suspect the EMFields meters are probably the same, though you would need to confirm with them.

For RF, Gigahertz are measuring peak levels using power flux density
https://www.gigahertz-solution…../314/hf32d – see Technical Data

On the other hand, EMFields Acoustimeter (which I use) measures peak values in V/M and time-averaged in uW/m2 (averaged over 2 seconds if I remember correctly). For reference I tend to use the peak v/m. EMFields do offer a conversion from v/m to PFD, but also warn that it is only valid for certain types of signal.There is some background information on peak vs average measurements on their website (http://www.emfields-solutions……imeter.asp)

Guidelines.

The Building biology RF guidelines are expressed in uW/m2, and are peak values. (see http://createhealthyhomes.com/…..glisch.pdf). They do not state what they are using for power frequencies. I would guess RMS, but that is just my guess – an enquiry to them would probably yield the answer.

What is clear, as you imply, is that RF measurement and guidelines are a fruitful source of confusion and possible mis-interpretation, especially as many authorities do not state whether they are referring to peak or average values when using PFD. This is without considering the preference of some authorities (including Prof Trevor Marshall) for using DBm for RF measurement. To be absolutely confident it would be worth checking specific meters with the manufacturer, and guidelines with whoever produces them.

January 14, 2017
4:40 pm
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xchcui
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peter williamson said
…What is clear, as you imply, is that RF measurement and guidelines are a fruitful source of confusion and possible mis-interpretation, especially as many authorities do not state whether they are referring to peak or average values when using PFD. This is without considering the preference of some authorities (including Prof Trevor Marshall) for using DBm for RF measurement. To be absolutely confident it would be worth checking specific meters with the manufacturer, and guidelines with whoever produces them.  

Yes,indeed.It is very confusing.As if that is not enough that there are many differents guidelines for the differents EM FIELD at different frequencies and there are different units of measurments and different EMF meters,we need,also,to rack our brain and to figure out if the parameters on each guidelines charts are a peak or average value,in order to compare them to the emfmeter results.
Anyway,your last post and your attached links help me alot to understand the issue
and i think that i understood,according to your explanation,how to use the guidelines chart with the emfmeter results.

Thank you very much for your help.Smile

October 16, 2017
1:52 pm
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downunder
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thank you helpful information.
I’m really new to this and on a steep learning curve, still lots to read and learn.
when you measure different frequencies do you add them altogether or multiple to try and work out an exposure limit when you are around different frequencies?
trying to work out how you can create a safe limit with different devices together.
for instance – multiple wi-fi and bluetooth devices, multiple inverters, electricity, mobile phones gsm
I haven’t bought Lloyd’s ebook, is that information in the ebook? happy to buy it if it is.
any other information source that can give me the 101 you know of?
thanks

October 17, 2017
12:14 pm
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peter williamson
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Hello downunder, and welcome to the forum.

You raise an interesting question, and one which I have not seen discussed. The general approach favoured by Building Biologists seems to be to take each type of radiation (power frequency, dirty electricity, microwaves) and reduce each one to their target level or ALARA (As Low As Reasonably Achievable). Multiple exposure in the microwave band is often mentioned as an issue (eg wifi + multiple phone masts), and most meters will aggregate the radiation in the microwave range (usually about 600MHz to 6 or 8 GHz – depending on the meter).

Adding different frequencies involves some slightly complicated maths, and I’m not sure how helpful it would be to try to add, for instance, power frequencies and microwaves. You might find some helpful info on http://www.powerwatch.org.uk/ (articles library) or http://www.emfields-solutions.com/. They have some good publications covering the basics, different types of appliances etc. And of course there’s lots of information on the main site here. These are the best introductory resources I know of. EHTrust.org is also worth a look.

October 18, 2017
4:44 am
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downunder
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Thanks Peter, appreciate it i’ll check them out. From what i’ve read so far i haven’t seen a conclusive study / test that clealy shows rf/emf as directly causing cancer. There are small numbers but nothing statistically relevant. As in the latest $25million us gov study such small numbers in males with cancer but also showed they live 8% longer. I see it as a huge missing link as that’s how it is in the real world of multiple frequencies. Each company / frequency on the court stand will say my product is safe here’s the tests. And say we can’t possibly test all sutuations. Government, standards or someone else is responsible. I suspect this where it causes other problems with multiple devices and clearly point to cancer and other health problems. When phone companies install new tower they say it’s perfectly safe on its own, here are the tests. But people have wi fi and power in their house as well as a minimum. Could be an exponential plotted curve i’d expect of standard units over time depending the mix?

October 23, 2017
3:05 pm
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downunder
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Does anyone know how to use the meter (Cornet ED88T) and convert the RF reading of mW/m2 to the Australia ARPANSA Standard, page 15 of PDF, table 2 shows it in W/kg. I’m guessing you record for 6 min in mW/m2 and come up with mWh/m2 and divide this by your body weight?
https://www.arpansa.gov.au/sit…..s/rps3.pdf
Very new to this, only got the meter today and doesn’t seem as easy as I thought to measure and compare against the standard.

On a side note I wonder if anyone has done a study and crunched the numbers on these two worl maps, by eye they seem to be highly correlated.

https://opensignal.com/reports…..le-network

http://globalcancermap.com/

. thanks
Dave

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