Emf shielding appled to car

yes, please find this study and link the priuschat posts. i hope they have comparitive non hybrid testing. and please see edthefox5's link in post #9.

 

with all due respect the left rear seat has a lot of EMF comparative to elsewhere in the Prius, also there's EMF near the steering wheel column, and left door sills front and rear. EMF is fairly easy to detect and EMF detectors are cheap. I think it would serve many on the board to just take a few measurements for themselves.

 

From what you say here, you've obviously made the tests yourself - why not share the results?

 

Sure there is EMF in the Prius, it is everywhere. Can you pickup a radio station or cell tower signal? Or anywhere near electricity? Get over it. Only those that are blind to physics will put any merit into this.

Read one of many real tests here from consumer reports: Mythbuster: EMF levels in hybrids

Test findings:​

We found the highest EMF levels in the Chevrolet Cobalt, a conventional non-hybrid small sedan.​

To conduct our measurements we used a sophisticated three-axis ELF/Magnetic Field meter. That gave us readings in milligaus units, the commonly accepted measure for magnetic fields. We measured EMF levels on all 13 vehicles under the same conditions. We took measurements at the driver’s right foot, knee, waist, and head when idling and driving around our simulated stop-and-go city-driving course, and while accelerating from 0 to 60 mph.​

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Here are some highlights from the tests:​

• For all vehicles, EMF readings were highest in the driver’s foot well and second-highest at the waist, much lower higher up, where human organs might be more susceptible to EMF. Typically, peak readings were highest under braking.​
• Some hybrid cars had readings similar to conventional cars. For instance, the Mini Cooper Clubman registered a maximum of 2 milligaus and the Toyota Prius 2.05. The 2008 Subaru Legacy exhibited 2.5 mG.​
• The Toyota Highlander hybrid had a peak reading of 0.6 mG and an average of 0.4 mG measured at waist level while the regular Highlander measured a nearly identical 0.5 peak and 0.45 average mG there.​
• The Chevrolet Tahoe Hybrid measured as much as 14 milligaus, but the conventional and otherwise similar Suburban only showed 0.8.​
• Among the 13 vehicles tested, the Chevrolet Cobalt had the highest peak readings, 30 mG at the feet and 16 mG at the knee.​

Considering you are on an internet forum, you have electricity around you somewhere, must have used a computer of some kind (desktop/laptop/tablet/phone) all of which in general output more EMF than the Prius.

This is all in your head. That is a real diagnosis sometimes, psychological beliefs can alter physical feelings. You think you are being harmed by X, and therefore you are. Same reason why sugar pills (placebos) work. You installing this expensive tin foil (no difference between what you got and the value food foil wrap at Walmart) made you feel better in the same exact way a sugar pill makes people with all sorts of ailments feel better. The truth sometimes hurts, but it is better to be informed.

 

With all due respect, my electrical engineering background finds the product description and specs exceptionally lacking. And I am not finding the manual online. Can you please look in the manual and let me know some details?

* What units are being measured?
* What is the claimed accuracy?
* What is detection sensitivity?

BTW, this review really pushes my skepticism of the device well over the edge:
"I run a Paranormal Investigation group ... and have years of experience with EMF detectors and meters. ... After testing and comparing to my extremely accurate professional meters (Lutron mG Professional Field Tester, Tri-Field meter, Mel meter, KII detector, Gauss master and even the EMF GhostMeter), I discovered this: -1- This device, not once, even came close to the readouts of the other meters. Tested MilliGauss mG, Gauss, micro-Tesla, Tesla, HgH, RF frequencies. In fact, the readout seems to be completely random and hardly ever duplicatable in exact repeat tests. -2- If you simply tap on the casing of the device - The number readout spikes. ..."
See more of the review here.

 

the point is you can utilize any EMF detector and get reasonable results for this type of application. Or do you not say so? This is not the model I or others have used, and I have not claimed that. If you're an electrical engineer why don't you take the measurements for us, you must have an EMF detector due to what is clearly demonstrated as superior knowledge about things that do not affect this discussion in anything but the most theoretical way.

I found that the EMF was higher than I am comfortable with. I do not share results on here often because of responses that are not helpful to an actual discourse. I will say it is much higher than the test quoted claims, I think they may have measured from the lowest area, since I have not found the footwell to be the maxium of EMF in the Prius.

Sorry but I'm not going to publish a multidimensional map on this with sources and calibrations of instruments. If it doesn't satisfy you test it yourself.

 

You're the one who said a few posts back: "with all due respect the left rear seat has a lot of EMF comparative to elsewhere in the Prius, also there's EMF near the steering wheel column, and left door sills front and rear."

What are the actual measurements, and where did they come from?

 

My point is simple spend $20 on a detector and know for yourself. If I posted a study you would rip it apart. So buy, rent or borrow an EMF detector and hold it in the prius in various areas. In terms of numbers expect more in the 75-200mG range if that is safe for you is another discussion that I am not sure has been sorted yet.

 

All of your measurements are completely useless unless you shield the entire vehicle from outside sources. This is why for things where these levels of radiation matter, they are stuck in an anechoic chamber shielded from the outside, and where they are accurately measured from the inside. You with your crappy meter in your garage or outside will never take an accurate reading.

The spectrum analyzers we have in the lab are a quarter of a million USD a piece for the lower end models. There is a reason why we pay for good equipment and why you can't just be any old monkey to use it.

 

you simply don't understand emf. it's everywhere and in every car. prius is lower than most.

 

there is no way the EMF in the prius is lower than most cars that run on 12v DC. Intellectually everyone needs to understand it is higher than most cars. There are more high power electrical draws, sources and transport than most cars, including the brakes, steering, and HSD, maybe not a tesla but other than that. You can see for yourself, I have not found any shielding in the passenger compartment.

It's not as high as a microwave, or the background low frequency EMF of the earth but its there and its real. There are interesting EMF properties in the Prius that you don't see often in terms of in your house. I'm not sure its dangerous but its there. Telling me I don't understand it when I studied physics on a major track and measured it is silly.

 

Then measure it, and you will find the same thing that every other report has found. The Prius is an order of magnitude better than many other vehicles (i.e. Chevy vehicles). And even then, it is in the "don't give a shit" region.

Your post also shows a lack of understanding of the physics you claim to have majored in. Hopefully not university level.

The electric fields without any shielding will be higher from the HV battery to the inverter and then even higher as it is boosted to the electric motors. However, magnetic fields require a current change. Therefore with good design you can have a very very high voltage system with very little EMF and similarly you can have boatloads of radiation from a poor design at low voltage. There is no direct correlation between high voltage and higher EMF. There is a correlation between high voltage and EF. But to get the "M" in EMF, you need huge current deltas.

The most prevalent area that these are found are inductive in nature. That includes motors (fans, or EV drive, etc) and SMPS's (switched mode power supplies).

Every vehicle has a bunch of SMPSs in them. Since SMPS's generally deliver lower power, sometimes designers use crappier supplies because they can get away with it. The Toyota SMPS's are very well designed from the ECU's I have cracked open. They tend to operate at a higher switching frequency, shielded well, and have great responses. Since there are many tens of these around any modern vehicle, a crappy design copy/pasted can account for a lot of electrically noise.
Fans like the HVAC fan will emit quite a lot of radiation as well. These are on all cars, not just the prius.

The only thing the Prius has that the others don't is a high voltage battery and inverter. If you look at the inverter design you will notice that very little back-EMF is produced. This is pretty usual since when you are using energy to make radio waves, it is lost and inefficient. This usually relates to lots of heat in the magnetic components. With the power being sent through the components all the time, if it were that inefficient it would be very hard to cool them with a basic radiator and have them last the life of the car.

 

I say not so. Before retirement, I used spectrum analyzers of the sort another respondent still uses, and even helped put some models out on the market. All that stayed with the employers when I left, but that doesn't mean I can't recognize some devices, such as the one you linked, as cheap junk that can't even describe what it purports to measure.

Two years ago, you asked:

It appears that you wrote me off the moment I asked for the ESR spec of your cap, and you haven't wanted to contribute anything helpful to actual electrical discourse, only FUD ever since. Junk 'studies' get ripped apart for very good reason.

 

Electromagnetic fields require AC voltages and their accompanying current changes. You usually measure only one of its two components,. Either the magnetic field at the frequency emitted or the electric field.

In order to generate electric fields you only need potentials, no current. These EM fields develop between the two conductors of differing potential. In a Prius most HV lines run close to their ground line or the car body. As both are very close to each other, fields are locally limited to the area between them. Outside of the gap area there is litte to no electric fields unless you design your system on purpose to do so.

Same for magnetic fields: no alternating currents required, just current. DC current makes static fields as do permanent magnets or a dude holding a magnet on you car's steel body for a second.

More current equals more field. High voltage reduced current for given transmitted power reducing magnetic fields. This is what magnetometers measure at low frequencies down to DC.

Anything stated in Gauss is looking at magnetic fields, anything stating V/m is looking for electric fields.
As said before, your copper mesh will only shield higher frequency electric fields and reduce high frequency magnetic fields via induction. Though copper mesh is pretty poor at it.

Magnetic fields and their accompanying friends such as flux and flux density can be very complicated to digest. Same for EM fields or EMF.
Just remember mGauss and EMF do not belong together. It is a unit for magnetic fields.

Do to the complexity of Maxwell's equations the health effects of these fields are an ideal playground of scaremongers and alternative medicine people.
Nothing is proven, they are always right with no evidence to show and all studies conducted on a large scale by governments, etc are full of errors. Conspiracy everywhere.

Typically in science, when it takes huge efforts trying to prove that there is an effect and you cannot prove it, the effect must be very small or does not exist.
At some point the alternative shit takes over. Folks thing there must be connection because they feel it, intuition tells them or some self proclaimed guru makes them believe so.
Unfortunately things in nature are not always simple and intuitive, they can be very complicated.
Just because something does something in a Petri dish does not mean it does the same thing in a person.

Man, wake up. You make yourself sick. A this is validated and undisputed .

PS science is my job. Measuring small magnetic fields in a high EMF and EM polluted environment was a big part of a project it ran for two years.

Again: if you believe it makes you sick, it does. I do not believe it and it does not make me sick. It is as easy as that.
You spend several hundred dollars to improve the car, you better feel an improvement. Guess what: you do. This is science at its best
Is it fully understood how it works? Unfortunately not, partly because it is very complicated. I have not spotted a good karma wave meter in Agilent's catalog so far.

Shaking heads


iPad ? - now Free

 

Small correction: in the third line it should read electric fields, not EM fields


iPad ? - now Free

 

As an alumnus of HP / Agilent's T&M operations, this comment made my day. A zillion thanks.

 

Any current applied through a wire will cause emf. the brakes also generate ac thats converted.

 

"Because I think it is" is not a valid argument. All the instrumented tests prove you wrong, but mere facts cannot effect "because I think it is". You want to find the largest sources of EMF in the Prius? Check near the ventilation fans. (which run at 12 volts)

'High power draws' and EMF are not directly related, a steady DC current has no real EMF unless you are moving with relation to the field. Rotating DC or AC do have EMF, which is why the fans are detectable. (Almost ever car has ventilation fans inside the passenger compartment, this is not unique to a hybrid)

EMF from outside the passenger compartment are largely blocked. Faraday cage - Wikipedia, the free encyclopedia

My 2008 Prius, and other things, EMF Measurements! | PriusChat

But I know, those are just facts.

 

You would be better off spending the $20 on a couple of six packs! Reliability, accuracy, and dependability don't come with a 20 buck price tag. If you are basing all your responses on $20 bucks, you wasted $19.98!
Everyone does get to put their 2¢ in, you get what you pay for!
Your reluctance to post your findings indicate they are not worth mentioning!
When I did a EMF reading, I at least posted all the test areas with pics indicating measured values.
I should take your word, I'll pass!

 

Reply: Robo, I have a compromised heart and brain from a diving accident a year ago, just after purchasing my Prius V. Like you, I love the car, however in putting my body back together, my gifted licensed healer found the Prius V putting out very high levels of radiation working against both my heart and brain function. Serious stuff. I have been looking for a solution other than getting rid of the car, which is the only alternative. Pay no attention to the pseudo responses below who use crude meters to justify their responses. Tesla shields the radiation. I have been tested while inside both the Tesla and Prius V running. No challenge in Tesla. Horrible response in Prius V, and my existing protection did not protect from the overwhelm, which surprised me. All indications are that what you have done has made a serious improvement in lowering your exposure, and may work well for me.