Author Topic: Measure electrosmog emitted by laptops or computers  (Read 16081 times)

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Offline jancelotTopic starter

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Re: Measure electrosmog emitted by laptops or computers
« Reply #25 on: January 29, 2017, 06:49:54 pm »
AARONIA AG also sells several meters, accessories and shielding materials, for example the Spectran HF-6060 V4 (10MHz - 6GHz):

http://www.aaronia-shop.com/products/spectrum-analyzer/handheld/rf-spectrum-analyzer-spectran-hf-6060-v4
 

Offline acbern

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Re: Measure electrosmog emitted by laptops or computers
« Reply #26 on: January 29, 2017, 08:03:27 pm »
Correctly measuring EMI is very complex. Not only do you need the correct spectrum analyzer (special versions are available, called e.g. EMI analyzer; they do measurements in accordance with EMI specific standards). You also need the proper environment and a calibrated set of antennas and an EMI chamber or a free area, with metal floor (very simplisticly speaking; detailled descriptions can be found on the net), or a TEM cell for smaller items. For most hobbyists, the effort goes beyond whats realistically doable.
Overall, measuring electrosmog from a device like a computer, which was certified to CE/FCC anyway, with most of the meters described above, is just not doable correctly. At best, you can get a qualitative overview, comparing e.g. two computers. That is not necessarily very meaningfull. You can have two equal numbers, but one may still be not compliant (having a strong spike at a specific frequency, while the other has the energy broadly distributed). So the bad news is, correctly measuring the EMI of a computer (which is a low level emitter), is complex and expensive.
In theory, if you find a cheap EMI antenna somewhere (i have never seen one, most are 2k up...), you could buy a 8590 spectrum analyzer (going up to 1.5GHz as a cheap solution, you get that below 1k. Not a quasi-peak analyzer, but will do. Move to your backjard which is located somewhere in an area with no EMI emitters around (industry facilities, radio stations...), do a scan without DUT, and do one with the DUT, and compare data. A metal mesh on the ground would be needed. All this is still far away from being standards-compliant, but is not too bad either. Dimensions are important (mesh size...., see information available on the internet). If properly set up, and with a good antenna in a suitable area, this could even be used as a setup for internal precompliance-testing, prior to doing an EMI certification.
 
 
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Offline jancelotTopic starter

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Re: Measure electrosmog emitted by laptops or computers
« Reply #27 on: February 12, 2017, 08:38:45 am »
A little update on the TES-593: use some accessory to keep it separated from your hand and body, since static electricity from a living organism can interfere with the measurements and increase the measured value. I don't know if it happens with Gigahertz Solutions or Aaronia hardware, but certainly does with the TES-593. It has a thread in the back to put there camera mounts or selfie sticks.
 

Offline tooki

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Re: Measure electrosmog emitted by laptops or computers
« Reply #28 on: April 02, 2017, 10:09:46 am »

Shocking grounding installation:



Good grief - Not only is that guy in the video overloaded his outlets (depending on what's running) but with that black sleeving he made absolutely sure those cords will have a pretty high thermal resistance to the rest of the world.  "Let me see how hot I can get these power cords!"

He should be less concerned about EMF and more more worried about a fire insurance inspection.... :palm:
Oh, it gets better: He's using the multimeter with the red probe on the V input and the black probe on the 10A input! Someone pointed this out on the youtube comments, this was his reply: "I don't know the difference between using the com vs the 10a plug but they both read the same voltage anyway.  The 10a plug has always worked for me but you're probably right. ?"  :palm:

So what is he actually measuring, then??
 

Offline helius

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Re: Measure electrosmog emitted by laptops or computers
« Reply #29 on: April 02, 2017, 10:35:08 am »
The amps jack is connected to the common jack by the current shunt. Misusing the meter that way has the effect of reducing the readings according to the voltage divider formed by the two impedances; since the shunt is very low impedance compared with the V input this has a small impact.
 

Offline Howardlong

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Offline tooki

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Re: Measure electrosmog emitted by laptops or computers
« Reply #31 on: April 03, 2017, 09:26:06 am »
The amps jack is connected to the common jack by the current shunt. Misusing the meter that way has the effect of reducing the readings according to the voltage divider formed by the two impedances; since the shunt is very low impedance compared with the V input this has a small impact.
Oh, duh. I know this. Serves me right for posting right after getting up in the morning, before my brain is awake...  :palm:  :clap: |O
 

Offline jeroen79

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Re: Measure electrosmog emitted by laptops or computers
« Reply #32 on: April 04, 2017, 11:46:44 am »
The amps jack is connected to the common jack by the current shunt. Misusing the meter that way has the effect of reducing the readings according to the voltage divider formed by the two impedances; since the shunt is very low impedance compared with the V input this has a small impact.
Unless he converted the fuse to an extremely high impedance on an earlier occasion. ;)
 
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