Measure electrosmog emitted by laptops or computers

[jancelot]

I would like to measure the electrosmog emitted by a particular laptop or desktop case, but the emissions related to normal operation. Wifi, bluetooth and such disabled.
I've seen that Retro-PC-Mania uses the TES 593 (10Mhz - 8GHz) to measure electrosmog in shopping malls, but I'm not sure it will fit my purposes.

I'm sure most manufactures comply with RF requirements by different approval seal or laws, but I have my doubts the values are still high.

What do you think?

[joeqsmith]

May not be as simple/inexpensive as you think to run a test like this with any sort of accuracy.   Maybe start by reading the standards and seeing what is required. 

[VK5RC]

Serious EMC testing can be very expensive and time consuming,  the Radio society of great Britain has an EMC committee and publishes regularly in the magazine RadCom.  I think the USA amateur radio society,  the ARRL,  also has a similar section.
A lot of cheap smpsu are very noisy in terms of RF. As a result I can't hear anything in HF radio at my place due to them.

[jancelot]

Thank you a lot for providing information about legal organizations, but I'm looking more specifically for a practical approach. No very high costs involved. Also, online information is important since I'm not living on either the United kingdom or the U.S.

My main interest is measuring equipment under $600 for example, which can provide numerical values for comparison.

All things said, looks like the TES 593 (10Mhz - 8GHz) is the recommended approach for general electrosmog measurements. There is also other  equipment able to measure frequencies from 20Hz to several kHz, but I think that's for other things.

[jancelot]

Video that is extremely helpful:


Stores and information:
EMF Safety Store
Less EMF
EMF Center

Shocking grounding installation:


Scary case of ungrounded iMac:

[helius]

Using a multimeter is a pretty piss-poor way to measure electric fields: the frequency range to which they are sensitive is generally limited to the SLF range (30 to 3000 Hz). If you are only measuring them for "feel-good" reasons like the fellow in those videos, OK... 
The idea that these fields have any effect on humans has been pretty much debunked. But EMI in the HF range is of particular concern to amateur radio users, and won't be shown using silly multimeter tests.

[jancelot]

Using a multimeter is a pretty piss-poor way to measure electric fields: the frequency range to which they are sensitive is generally limited to the SLF range (30 to 3000 Hz). If you are only measuring them for "feel-good" reasons like the fellow in those videos, OK... 
The idea that these fields have any effect on humans has been pretty much debunked. But EMI in the HF range is of particular concern to amateur radio users, and won't be shown using silly multimeter tests.

What range are you talking about? Because "HF" range depends who you ask to.

[helius]

What range are you talking about? Because "HF" range depends who you ask to.

https://en.wikipedia.org/wiki/High_frequency (3 to 30 MHz, including most of the shortwave band). Radio also uses other bands, of course. For some purposes, it is undesirable to have EMI/RFI over a wide swath of the spectrum:

[HighVoltage]

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

[chris_leyson]

As for measuring EMF from your computer, EMF is electromotive force and strictly speaking it should RFI but there you go. I've always found common mode interference to be a big problem when trying to use software defined receivers or for that matter anything that is sensitive and wide band. Laptop power supplies are usually the culprit but sometimes the laptop itself can generate common mode noise on USB ports. I've found desktop computers are usually quieter.

[Monkeh]

 

[jancelot]

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

It looks great quality but it's missing the newer 5GHz band for WiFi for consumer electronics and the also the 5.9 GHz (802.11p) for vehicular communication systems. I can see that there are more expensive kits from Gigahertz Solutions like the MK70-3D PLUS 2.2

[jancelot]

Here are some instruments that I've found:

* AlphaLab Trifield 100XE meter: measures all three types of electromagnetic field: AC magnetic field, AC electric field, and radio (including microwaves). The magnetic and electric detectors are 3-axis
* TES 593 meter: to measure electrosmog 10Mhz - 8GHz. Sensor type is electric field, isotropic, 3-dimensional.
* magnetic sciences MC162: 2 kHz to 1 MHz AC magnetic field sensor, with BNC connector.
* magnetic sciences 6GHz EMI probes: wideband single-axis probes allow low-cost measurement of magnetic and electric field strength, locating sources of electromagnetic interference (EMI) and radio frequency interference (RFI), microwave emissions, electromagnetic compatibility and EMC / EMI / RFI testing, and troubleshooting RF circuits.
* AlphaLab UHS2: AC magnetic field meter, 13 Hz to 75 kHz, true 3-axis magnitude.
* Gigahertz Solutions RF-ANALYSER KIT HFE35C: EMF meter 27 MHz - above 2.7 GHz.
* EMFields AM-10 acoustimeter: microwave detector ranging 200 MHz - 8GHz. Has visual scales, LCD screen and speaker.
* KEYSIGHT FIELDFOX and HSA: handheld spectrum analyzers, ranging from 5kHz to 50 GHz.
* EMDEX Lite Magnetic Field Meter: Versatile Personal Magnetic Field Measurement System. 0.1 - 700 mG(0.01 to 70 ?T). 40 - 1,000 Hz. True RMS.

[MisterDiodes]

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....

[jancelot]

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

Gigahertz Solutions RF-Analyser are single axis? It's not specified on the website.

[HighVoltage]

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

Gigahertz Solutions RF-Analyser are single axis? It's not specified on the website.

Good question, I do not know but I would suspect it to be a single axis analyzer
`

[HighVoltage]

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

It looks great quality but it's missing the newer 5GHz band for WiFi for consumer electronics and the also the 5.9 GHz (802.11p) for vehicular communication systems. I can see that there are more expensive kits from Gigahertz Solutions like the MK70-3D PLUS 2.2

They have one version that goes to 6 GHz and another one that goes to 10 GHz
https://www.gigahertz-solutions.de/de/messtechnik/

[jancelot]

Gigahertz Solutions RF-Analyser are single axis? It's not specified on the website.

Good question, I do not know but I would suspect it to be a single axis analyzer
`

Ok I've found that the HFE35C can measure from 27 MHz to 6 GHz, but the actual range depends on the antenna used:
- The LogPer aerial supplied with the meter covers a frequency range of approx. 800 MHz to 2700 MHz. That is the logarithmic-periodic antenna (or aerial) and is exceptionally directional.
- For a quantitative measurement of frequencies below 800 MHz with the HF59B, Gigahertz Solutions provides the active, horizontally isotropic ultra broadband antenna UBB27_G3 responding to frequencies from 27 MHz right up to more than 3.3 GHz.

Source:
https://www.gigahertz-solutions.de/media/pdf/g0/fa/cb/530-054_Manual_HF58B-HF58Br-HF59B_rev.6-0_EN.pdf
https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/338/hf59b?number=530-054

You could use a HFE35C Gigahertz Solutions RF-Analyser kit.
They work pretty well to detect all kinds of electrical noise.

https://www.gigahertz-solutions.de/en/emf-meters/high-frequency/meters/383/hfe35c?c=137

It looks great quality but it's missing the newer 5GHz band for WiFi for consumer electronics and the also the 5.9 GHz (802.11p) for vehicular communication systems. I can see that there are more expensive kits from Gigahertz Solutions like the MK70-3D PLUS 2.2

They have one version that goes to 6 GHz and another one that goes to 10 GHz
https://www.gigahertz-solutions.de/de/messtechnik/

i see. Actually some meters can measure more bandwidth if you use additional antennas than the ones included by default. In that case you want to buy kits, like the ones mentioned in that graph.

https://www.gigahertz-solutions.de/en/cat/index/sCategory/137

[jancelot]

Using a multimeter is a pretty piss-poor way to measure electric fields: the frequency range to which they are sensitive is generally limited to the SLF range (30 to 3000 Hz). If you are only measuring them for "feel-good" reasons like the fellow in those videos, OK... 
The idea that these fields have any effect on humans has been pretty much debunked. But EMI in the HF range is of particular concern to amateur radio users, and won't be shown using silly multimeter tests.

You are right. My Brymen BM257S has an AC voltage range of 50 to 400 Hz.
The Brymen 869S has a range from 20 Hz to 100 kHz which is pretty good, but the accuracy varies depending on frequency and voltage range.
The Fluke 87 V has an AC voltage range of 20 kHz with low pass filter; 3 db @ 1 kHz

[jancelot]

Gigahertz Solutions EMF meters:





For the low frequencies, we measure electric fields and magnetic fields separately.

• The ME3030B is the entry level M&E meter, costs about €150, range 16 Hz - 2 KHz (compensated, better than -2 dB), electric field strength from 1 to 1999 V/m (against ground potential), magnetic flux density from 1 to 1999 nT, acoustic signal. It's single-axis like most of the low frequency meters
• The NFA1000 is the top of the line for the low frequency meters. The frequency range is 5 Hz to 1000 KHz (compensated, +/- 2 dB), with 3D sensors for both electric field strength and magnetic flux density (3-axis). Cost is €1934.

For the high frequency, we measure the electromagnetic radiation and ideally on the far field. Depending on the meter, there are two available antennas: one is the logarithmic periodic (highly directional) and the other is the isotropic. Either antenna has a different frequency range. Additional accessories and filters are available.

• The entry level meter is the HF32D, which costs about €250. Has a range of 800 MHz - 2.7 GHz, with a display of 1 µW/m² up to 1999 µW/m²
• The top of the line are the HF59B (27MHz - 2500MHz, €1166) and the HFW59D (2.4GHz - 10GHz, €1166).

There are also kits available. The most complete kit is the ELECTROSMOG MEASURING KIT "PROFI PLUS" MK70-3D PLUS 2.2, costs €5980.

[Kleinstein]

With those instruments labeled to measure electro-smog one has to be careful. It like a red hearing to have the bull-shit alert button ready.

If they use arguments like negative health effects of electro-smog, I would not take the rest too serious.   

To get anything useful for EMI measurements you need frequency specific data and thus more than just a single number reading. Usually results are in dB, not just linear numbers as there is quite a large power range.

[T3sl4co1l]

I would like to measure the electrosmog emitted by a particular laptop or desktop case, but the emissions related to normal operation. Wifi, bluetooth and such disabled.
I've seen that Retro-PC-Mania uses the TES 593 (10Mhz - 8GHz) to measure electrosmog in shopping malls, but I'm not sure it will fit my purposes.

I'm sure most manufactures comply with RF requirements by different approval seal or laws, but I have my doubts the values are still high.

What do you think?

"Duh" solution:

1. Inspect the label on the equipment.
2. Find the FCC ID.
3. Enter the FCC ID into the FCC database search.
4. Read the registered measurements.

Tim

[jancelot]

With those instruments labeled to measure electro-smog one has to be careful. It like a red hearing to have the bull-shit alert button ready.

If they use arguments like negative health effects of electro-smog, I would not take the rest too serious.   

To get anything useful for EMI measurements you need frequency specific data and thus more than just a single number reading. Usually results are in dB, not just linear numbers as there is quite a large power range.

Serious manufacturers never say that electric/magnetic fields or electromagnetic radiation is good or bad. They just release products to measure things and provide specifications. But I do not agree that certain levels are not dangerous.

About frequency data, you mean representing the values for electric and magnetic fields in the frequency domain (using Fast Fourier Transform)? What hardware would that require?

Some information I've found:
- Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth- Ionosphere Waveguide (ResearchGate)
- Propagation of ELF Radiation from RS-LC System and Red Sprites in Earth- Ionosphere Waveguide (pdf)

[Kleinstein]

The normal, more accurate way of looking at electromagnetic emissions is using a spectrum analyzer. Modern version might use a kind of FFT for some of this, classical ones are more like a scanning receiver, measuring a small frequency band at a time. With a limited dynamic (and often frequency) range a modern DSO with FFT function could be used.
One usually also needs a reasonably shielded and absorbing room and well calibrated antenna.

[jancelot]

The normal, more accurate way of looking at electromagnetic emissions is using a spectrum analyzer. Modern version might use a kind of FFT for some of this, classical ones are more like a scanning receiver, measuring a small frequency band at a time. With a limited dynamic (and often frequency) range a modern DSO with FFT function could be used.
One usually also needs a reasonably shielded and absorbing room and well calibrated antenna.

Can you tell us a specific set of hardware? Digital Storage Oscilloscopes and other electronic equipment can generate their own electric and magnetic fields and interfere with the measurements, specially if you get the signal from an antenna instead of coaxial shielded cable. The Keysight Handheld Spectrum Analyzers are promoted as very good shielded (MINUTE 3:39):