Measuring Cell Phone Radiation (Extech 480836 ?)  - Page 1
Forum section: electronics / testgear

author: Kobus
author_rank: Contributor
timestamp: February 16, 2014, 10:06:18 pm
content: A local cellphone provider has installed a new 3G 2.1 GHz base station < 10 meters from my apartment.I know the whole subject of cellphone radiation being harmful is very confusingI'd like to play it safe.Firstly, does anyone know what the official guidelines for maximum exposure to RF signals are ?Secondly, how do I measure the field strength ?My first guess was to use a spectrum analyzer.I just don't know if measuring the electrical component of the wave is sufficient.Also, I wouldn't know how to get an absolute measurement.My next guess would be to find something equivalent to a handheld sound pressure meter.You set the desired frequency band and then just watch the reading as you walk about.The closest I have found is the Extech 480836http://www.extech.com/instruments/product.asp?catid=57&prodid=351From what they say, it only works on 900MHz, 1800MHz, and 2.7GHz. All other bands are "for reference purposesonly".Does anyone have any experience with this meter or anything similar ? Could this do the job ?ThanksKobus

author: KJDS
author_rank: Super Contributor
timestamp: February 17, 2014, 08:03:38 am
content: Any Spectrum analyzer will do, but you need an E field probe with it. The radiation limits are defined in ICNIRP and for a normal large basestation then then field drops below the limit about 2m from the antenna. A wall also tends to drop the level by about 10dB so you're very unlikely to suffer from it. A picture would be useful.

author: hgg
author_rank: Frequent Contributor
timestamp: February 17, 2014, 12:28:29 pm
content: Hi,Here are the exposure limits:http://www.aaronia.com/basics/limits/international-exposure-limits/I wouldn't trust my life on ICNIRP's limits though...Aaronia has a great collection of "electrosmog" meters.http://www.aaronia.com/I have the Spectran HF-2025E and has been working perfectly for years now. Only thing Idid was to upgrade its battery. With it, you will also discover some 'killer' wifi ADSL routers as well.There are some that are transmitting continuously without sending or receiving any data.and probably with more power than your local mobile phone station.George.

author: Psi
author_rank: Super Contributor
timestamp: February 17, 2014, 12:48:21 pm
content: Crunch some numbers to see how the cell tower RF output at 10meters and through a wall compares to a generic 200mW wifi access point sitting 1/2 a meter from you on your computer desk.(i dont know the answer but it might put things into preservative or at least allow you to compare it to something familar)

author: hgg
author_rank: Frequent Contributor
timestamp: February 17, 2014, 12:53:48 pm
content: If his appartment/house is several meters below the top of the transmitting aerial thenhe might not have any problems because of its close proximity.Buying the meter though would be a good idea.

author: KJDS
author_rank: Super Contributor
timestamp: February 17, 2014, 01:27:26 pm
content: Quote from: Psi on February 17, 2014, 12:48:21 pmNow crunch the numbers comparing it to a cellphone transmitting 600mW held 1cm from your ear.

author: Kobus
author_rank: Contributor
timestamp: February 17, 2014, 05:44:46 pm
content: The Spectran HF-2025E seems perfect for the job. Much easier to walk around with than a real SA.Does it give readings for a particular band ? The cheaper ones I have come across give a total readingfor all frequencies together.The base station is on the roof of my building, It seems quite small. My apartment is one floor downand about 4 meters away from the antenna. The adjacent building is one floortaller so they have windows facing onto the antenna. Across the street there is a housein line of sight as well. All of us are in this together. If radiation levelsexceed regulations in any of our homes we intend taking appropriate action.I hope to post some readings of the base station as well as those of my cellphone, routerand DECT phones once I get a meter. I'd also like to climb onto the roof to measure signalstrength there and get some photos.And BTW it is normal for wifi access points to continually send out beacons even whenno clients are connected. I believe the default is usually around 10 beacons per second.

author: KJDS
author_rank: Super Contributor
timestamp: February 17, 2014, 05:55:43 pm
content: If you're beneath the antenna you'll be a long way under the limits. If you're more than two meters away in front of the antenna you'll be under the limits.It does seem odd that they didn't just mount it on top of the taller building.

author: hgg
author_rank: Frequent Contributor
timestamp: February 17, 2014, 06:33:27 pm
content: QuoteYes, you can select a band, a frequency range and you can setup any parameter you can imagine.It comes with all the usual bands already programmed, like GSM900, UMTS, Wifi, DECT etc. You canalso listen to the band with AM. It has an internal speaker. The software is nice as well. The unitwill also show you the various exposure limits in real time.The other positive thing, is if in the future want a higher bandwidth unit, you can send the oneyou own back to them and you will pay the difference for the new one.I want to buy their 3D EMF meter buy they are quite expensive.QuoteExactly.I am very curious to see what are the readings when you are next to the antenna.

author: mos6502
author_rank: Frequent Contributor
timestamp: February 17, 2014, 09:57:37 pm
content: Cell phone "radiation"? On an EE forum? You gotta be shitting me. What's next, chemtrails worrying you? Earth rays? My advice, don't worry. Take some Bach flower remedies and you'll be fine.

author: Richard Head
author_rank: Frequent Contributor
timestamp: February 18, 2014, 10:10:13 am
content: Radio frequency emissions are non-ionising radiation.The worst that can happen is localised biological heating.You will get more harmful radiation by exposing yourself to sunlight as sunlight IS ionising radiation.And no, I don't work for a cellphone company!Dick

author: Psi
author_rank: Super Contributor
timestamp: February 18, 2014, 11:29:32 am
content: Quote from: KJDS on February 17, 2014, 01:27:26 pmThat's a bit different as it's only temporary exposure when your on a call verses permanent Wifi or 3G nearby 24/7

author: hgg
author_rank: Frequent Contributor
timestamp: February 18, 2014, 11:54:45 am
content: Quote1) Immunohistopathologic demonstration of deleterious effects on growing rat testes of radiofrequency waves emitted from conventional Wi-Fi devices.http://www.ncbi.nlm.nih.gov/pubmed/224658252) Use of laptop computers connected to internet through Wi-Fi decreases human sperm motility and increases sperm DNA fragmentation.http://www.ncbi.nlm.nih.gov/pubmed/221126473) Modulation of wireless (2.45 GHz)-induced oxidative toxicity in laryngotracheal mucosa of rat by melatonin.http://www.ncbi.nlm.nih.gov/pubmed/234790774) Effects of selenium and L-carnitine on oxidative stress in blood of rat induced by 2.45-GHz radiation from wireless devices.http://www.ncbi.nlm.nih.gov/pubmed/193964085) Non-Thermal Effects and mechanisms of interaction between electromagnetic fields and living matterhttp://www.icems.eu/papers.htm?f=/c/a/2009/12/15/MNHJ1B49KH.DTL6) Replication of heart rate variability provocation study with 2.4-GHz cordless phone confirms original findings.https://www.ncbi.nlm.nih.gov/pubmed/236756297) WI-FI ELECTROMAGNETIC FIELDS EXERT GENDER RELATED ALTERATIONS ON EEGhttp://www.istanbul.edu.tr/6internatwshopbioeffemf/cd/pdf/poster/WI-FI%20ELECTROMAGNETIC%20FIELDS%20EXERT%20GENDER.pdf8- Drosophila oogenesis as a bio-marker responding to EMF sources.http://www.ncbi.nlm.nih.gov/pubmed/239151309) Modulator effects of L-carnitine and selenium on wireless devices (2.45 GHz)-induced oxidative stress and electroencephalography records in brain of rat.http://www.ncbi.nlm.nih.gov/pubmed/1963707910) 2.45-Gz wireless devices induce oxidative stress and proliferation through cytosolic Ca²? influx in human leukemia cancer cells.http://www.ncbi.nlm.nih.gov/pubmed/2248992611) Melatonin modulates wireless (2.45 GHz)-induced oxidative injury through TRPM2 and voltage gated Ca(2+) channels in brain and dorsal root ganglion in rat.http://www.ncbi.nlm.nih.gov/pubmed/2201978512) Effects of wi-fi signals on the p300 component of event-related potentials during an auditory hayling task.http://www.ncbi.nlm.nih.gov/pubmed/2171413813) 2.45 GHz microwave irradiation-induced oxidative stress affects implantation or pregnancy in mice, Mus musculus.http://www.ncbi.nlm.nih.gov/pubmed/2333484314) Mobile phone mast effects on common frog (Rana temporaria) tadpoles: the city turned into a laboratory.http://www.ncbi.nlm.nih.gov/pubmed/2056076915) Electromagnetic waves of 900 MHz in acute pentylenetetrazole model in ontogenesis in mice.http://www.ncbi.nlm.nih.gov/pubmed/1460082116) Microwaves and cellular immunity. I. Effect of whole body microwave irradiation on tumor necrosis factor production in mouse cells.http://www.ncbi.nlm.nih.gov/pubmed/1061944517) Stimulation of murine natural killer cells by weak electromagnetic waves in the centimeter rangehttp://www.ncbi.nlm.nih.gov/pubmed/1054482818) Epidemiological evidence for a health risk from mobile phone base stations.http://www.ncbi.nlm.nih.gov/pubmed/2066241819) Cognitive impairment in rats after long-term exposure to GSM-900 mobile phone radiationhttp://www.ncbi.nlm.nih.gov/pubmed/1804473720) Effects of pulsed electromagnetic fields on cognitive processes - a pilot study on pulsed field interference with cognitive regeneration.http://www.ncbi.nlm.nih.gov/pubmed/1518080621) Microwaves and cellular immunity. II. Immunostimulating effects of microwaves and naturally occurring antioxidant nutrients.http://www.ncbi.nlm.nih.gov/pubmed/1061944622) Bone morphogenetic protein expression in newborn rat kidneys after prenatal exposure to radiofrequency radiation.http://www.ncbi.nlm.nih.gov/pubmed/1504263123) Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phoneshttp://www.ncbi.nlm.nih.gov/pubmed/12782486hgg.

author: taemun
author_rank: Regular Contributor
timestamp: February 18, 2014, 12:46:38 pm
content: Quote from: hgg on February 18, 2014, 11:54:45 amI can't go through them all, but in particular: any time I read "Epidemiology" I think of the first sentence of the wiki article:Quote from:http://en.wikipedia.org/wiki/EpidemiologyPatterns don't make a causal link.If the rest of the articles were describing a cause and effect, then good. If they were postulating on a means for the interaction, then great.Quote from:http://www.who.int/mediacentre/factsheets/fs193/en/

author: amyk
author_rank: Super Contributor
timestamp: February 18, 2014, 01:29:06 pm
content: This is the perfect opportunity to post this article again:http://mybroadband.co.za/news/wireless/11099-massive-revelation-in-iburst-tower-battle.html

author: taemun
author_rank: Regular Contributor
timestamp: February 18, 2014, 02:53:50 pm
content: Quote from: amyk on February 18, 2014, 01:29:06 pmWhilst I generally don't condone anecdotal evidence (this doesn't really say that mobile radiation doesn't/can't effect people, just that in this case it seems to be a powerful placebo), this was a good one.I particularly like the first comment from Robin which goes on and on about how it's the QAM's fault ("known for extreme transitions and full spectrum").AM Radio is fine, though:Quote from: RobinWe get similar news articles in Australia, with reference to wind turbines. (I'm sure there's been one about mobile towers as well...)

author: Kobus
author_rank: Contributor
timestamp: February 18, 2014, 05:39:07 pm
content: Quote from: mos6502 on February 17, 2014, 09:57:37 pmOkay, I suppose it was inevitable. It's a good thing my flame thrower is out-of-orderCall it what you want but RF signals are most definitely real and quantifiable. I turned to EEVBlog to find outthe best way to measure the field strength.What IS up for discussion is whether there are are adverse health effects aside from thermal heating.Thanks to Hgg we have plenty food for thought. Everyone is welcome to peruse and evaluate allavailable data.I personally don't buy all the quacky web site's anecdotal "evidence" and "theories".On the other hand, I don't want my family to be Guinea pigs. As long as RF levels are clearly withinrecommended limits, I'll be happy.As an aside, I originally titled this thread "Measuring EMF signal strength". I got a handful of views and zero replies.The next day I renamed it to "Measuring Cell Phone Radiation" and then the fun began.

author: tibim
author_rank: Newbie
timestamp: February 18, 2014, 07:15:05 pm
content: Indeed "heating of tissue" is currently the only widely scientifically accepted result of RF energy on biological organisms. However, as you can note by the responses in this thread, the latest research is suggesting there are many more possible negative effects. You are very right in being concerned about the level of RF you are being exposed to.The most basic method of measuring RF field strength involves a wire and a multimeter(set to measure mV AC). For ease of calculation the wire should be 1 meter long and insulated except at each end where + and - leads from a multimeter are attached. The wire should be straight and placed vertically or horizontally. In order to determine this you need to know which way the electric field from the transmitting antenna is oriented(is the transmit antenna horizontal or vertical?). Probably vertical for cell phone systems. You may just try both and get a more comprehensive reading; then you will know if it's harming you more while standing or sleeping.As works with any antenna, induction of nearby RF energy will lead to a current and voltage potential between the two poles of your wire(receiving antenna) which can be measured using your multimeter. Field strength is then reported in Volts/meter.I have not tried it before and would assume it would help to have a very sensitive multimeter along with logging ability for ease of capturing and recording data for analysis.Hope this helps.**I was thinking about this and realized the measurement may be more difficult as ordinary multimeters can not measure AC @ the higher frequencies used for cell systems. These used to be on 900MHz but I think some of the newer tech is around 2GHz.Maybe someone here knows and can chime in with the proper piece of equipment needed to make such a measurement accurately.tibim

author: bench_knob
author_rank: Regular Contributor
timestamp: February 23, 2014, 12:30:28 am
content: Quote from: KJDS on February 17, 2014, 01:27:26 pm

author: Macbeth
author_rank: Super Contributor
timestamp: February 23, 2014, 10:39:54 pm
content: MOD EDIT: Hateful and racist comment removed.

author: EEVblog
author_rank: Unknown
timestamp: February 24, 2014, 05:46:02 am
content: Quote from: Kobus on February 18, 2014, 05:39:07 pmThis is how it's done properly at a measurements lab:

author: VK5RC
author_rank: Unknown
timestamp: February 24, 2014, 08:42:05 am
content: As an amateur radio operator, at times in the microwave range, and I am not convinced of any proven adverse effects of EMR if guidelines are followed. A calculator allowing quite accurate calculation of field strength (from power, frequency, distance and antenna gain) is available from the vk3um website. Field measurement is very complex and expensive.

author: AlfBaz
author_rank: Super Contributor
timestamp: February 24, 2014, 09:59:15 am
content: Seeing how some heating is the predominant effect, I wonder if you placed two small vessels of water near each other, shielded one and then dropped a couple of temp probes in, possibly running them through differential amplification allowing you to null them out prior to test, would yield any noteworthy measurements

author: MrAureliusR
author_rank: Unknown
timestamp: February 24, 2014, 12:30:57 pm
content: You know what REALLY grinds my gears? All these people blocking hydro workers from installing smart meters because they think the 'radiation' emitted by them is going to turn their families into mutants...I always ask them, do you own a cellphone? And they give a blank stare... yeah, why do you ask? Because it's emitting as much 'radiation' as your smart meter does, and your cellphone does it 24/7 whereas the smart meter only sends data intermittently...I know this is a bit O/T but I just had to get that off my chest. Smart meters will help save power and help reduce carbon emissions. PERIOD.

author: amyk
author_rank: Super Contributor
timestamp: February 24, 2014, 12:37:34 pm
content: Quote from: AlfBaz on February 24, 2014, 09:59:15 amYou will probably get some effect but going outside on a sunny day will give you a lot more heating than the RF from your phone.

author: mos6502
author_rank: Frequent Contributor
timestamp: February 24, 2014, 01:05:02 pm
content: Also,Relevant part is at 10:20.

author: MrAureliusR
author_rank: Unknown
timestamp: February 24, 2014, 01:14:07 pm
content: Quote from: mos6502 on February 24, 2014, 01:05:02 pmBest show ever! Love Penn and Teller!

author: AlfBaz
author_rank: Super Contributor
timestamp: February 24, 2014, 01:16:10 pm
content: Quote from: amyk on February 24, 2014, 12:37:34 pmI was more interested inmeasuringthe effect than it's potential for harm

author: zapta
author_rank: Super Contributor
timestamp: February 25, 2014, 04:12:15 pm
content: Regardless if the tower causes actual harm or not, having it next to your apartment may reduce its market value and is some jurisdictions sellers have legal obligation to disclose things like that to the buyer.

author: HighVoltage
author_rank: Super Contributor
timestamp: March 01, 2014, 12:07:46 pm
content: One simple instrument to use, is the GIGAHERTZ Solutions, HFE35Chttp://www.ebay.de/itm/HF-Messgerat-HFE35C-Elektrosmog-/181253371083?pt=Mess_Pr%C3%BCftechnik&hash=item2a338af4cb

author: Macbeth
author_rank: Super Contributor
timestamp: March 01, 2014, 08:39:46 pm
content: Quote from: zapta on February 25, 2014, 04:12:15 pmOh, the whole NIMBY nonsense. I believe in the USA someone sold a house to the buyers without warning them that it had a history of hauntings. Apparently the buyers won damages from this nonsense!I would gladly buy a "haunted" house or one next to a transmission tower if it means I get 50% knocked off.

author: bench_knob
author_rank: Regular Contributor
timestamp: March 28, 2014, 10:21:13 pm
content: Quote from: Macbeth on March 01, 2014, 08:39:46 pmAll I know is that one of our microwave scientists at ITT Defense, in the lab one day admonished some of the guys for carrying around cell-phones in front pocket, "ya wanna cook your nuts?"Heh hehbench knob

author: Macbeth
author_rank: Super Contributor
timestamp: March 28, 2014, 11:57:54 pm
content: QuoteITT? I hear lots of crap about them being an un-accredited "university" that takes the lowest dregs in on ridiculous payment plans for a so called education (if ticking boxes is a skill). They all end up flipping burgers like they would have done, only loaded with $x0,000's of debt to ITT.Do they really have scientists in ITT anymore? If so, why?

author: bench_knob
author_rank: Regular Contributor
timestamp: March 29, 2014, 05:10:07 am
content: Quote from: Macbeth on March 28, 2014, 11:57:54 pm>ITT? I hear lots of crap about them being an un-accredited "university"Re; the school, I don't know anything about it other than having seen a few ads on TV over the years?! And I don't know anyone who has attended the school either, although I 'researched' the subject on WikiPedia tonight, which says that one of the (162) ITT Industries divisions, twenty years ago spun off the school. We have had nothing to do with them since.So what was your point?>Do they really have scientists in ITT anymore? If so, why?Re; ITT Industries, here's a few examples of the things that 'we' collectively do:ITT is the prime contractor for the new soon to be turned-on for public service L2C GPS System for Earth.- L2C SVs, we designed and fabricated the birds, (lots of orbital navigation, ionospheric physics, & RF stuff),- L2C Control Segment GPS RXs, (DSP, DOPs physics, uWave & RF stuff) (my engineering),- SINCGARS (lots of packet, digital, & RF stuff),- RADAR Systems, military and commercial sectors, (lots of DSP & uWave stuff),- Soldier WaveForm Radio (lots of DSP, & RF packet stuff),- MMCX, SMA, SMB, 'N', etc; and other connectors & waveguides (lots of RF stuff),- Night Vision,- PowerTrain: ships, trains, etc,- Water Purification Systems,- Desalination Purification Systems,and lots of other high tech stuff that is ITAR constrained.My work the L2C GPS Control Segment Receiver. A rack mounted, expensive, complex, multi-processor, microwave digital-signal-processor. This 'radio' listens to the timing transmitted by the L2C GPS constellation in orbit, performs precision measurements, which are encrypted and routed to the National Geospacial Intelligence Agency an subagency of the US DoD, where other scientists, make adjustments, to uplink to the SVs in orbit. Oh, BTW, these SVs are cesium locked.In our business unit, we have running around in the cafeteria, around a dozen or so physicists, math scientists, RF scientists, computer scientists, et cetera. We are just one of the groups in one division out of the 162 divisions. Last count, on our multi-national corporate network, we hosted 57,000 PC workstations.bench knob