EMF Meter Accuracy — What ±6 dB Really Means

Not many people read instructions or specifications — they never have and probably never will. So when people buy EMF meters, they often overlook the specs that matter, like the RF (Radio Frequency) accuracy of ±6 dB, and just assume the meter is accurate because it comes with a calibration report — even though they haven’t looked at or read the report themselves.

So what does that ±6 dB accuracy figure — quoted in RF meter manuals, including the popular Safe & Sound Pro II — actually mean?

Let’s break it down:

• 1 µW/m² could be reported as anywhere between 0.25 µW/m² and 4 µW/m²

• 10 µW/m² could be shown as between 2.5 µW/m² and 40 µW/m²

• 1,000 µW/m² could read anywhere from 250 µW/m² to 4,000 µW/m²

  
  

Depending on the meter you own, you could be underestimating or overestimating the RF levels in your environment. Some manuals include a frequency response curve, which shows where the meter over- or under-responds across the RF spectrum — but this is only useful if you know what frequencies you’re actually dealing with.

(Local antenna location websites can help with this.)

For example, if you look at the Safe & Sound Pro II response curve, you’ll see it over-reads around common frequencies like:

• Wi-Fi & Bluetooth (2.4 GHz)

• Australia NBN Fixed Wireless (2.3 GHz & 3.5 GHz)

• LTE/4G/5G at 2.6 GHz

• 5G at 3.6 GHz

  
  

These are problematic frequencies in many homes and workspaces. So if you can’t reach Building Biology recommended RF levels, don’t panic — you may already be hitting those markers without knowing it, and the meter is simply over-reporting.

Every meter has a different RF response curve — and that’s why readings can vary significantly between models, especially in complex environments with a mix of signal sources.

High-end Gigahertz Solutions RF meter kits are among the most accurate broadband RF meters, with a response of ±3 dB. But they require two separate RF meters and are bulky and expensive, which is why the Safe & Sound Pro II remains a popular choice for most people.

Real-Time RF Spectrum Analyzers

The only way to get a truly accurate flat response is with a real-time RF spectrum analyzer, like the Aaronia V6, with calibrated antennas and RTSA-Suite PRO analysis software. But these systems are very expensive (AU$10K–50K) and too complex for most users.

Also note: real-time RF spectrum analyzers often report much higher RF readings in congested areas than broadband RF meters, because they capture and sum individual frequency channel power levels in real time — something broadband meters cannot do.

Which Meter Should You Buy?

Personally, if I’m not measuring homes for clients and want to keep things minimal as someone highly electro-sensitive, the Mito Meter and E-Smog Spion 5G combo would be more than adequate as a simple and effective kit.

The E-Smog Spion 5G has arguably the best sound in the industry, covering 50 Hz to 8 GHz.

And sound doesn’t lie — it’s like a photo that tells a thousand words.

For me, it’s not about numerical accuracy anymore; I’m not interested in crunching numbers.

With the Spion, you can hear the crackling of sferics in natural EMF settings and quickly learn what a healthy environment should sound like across the spectrum. The goal, of course, is to replicate those conditions in your own living space. 

The Spion 5G doesn’t measure magnetic fields, though — and that’s where the Mito Meter comes in. Just like the best camera is the one you have with you, the best EMF meter is the one you actually carry. The Mito Meter even fits in a jeans coin pocket, making it the perfect personal screening tool.

For EMF professionals, it’s a different story. The Safe & Sound Pro II + EM3 kit, or a high-end Gigahertz Solutions kit combined with a dirty electricity testing kit (or portable AM radio for non-professionals), will handle most professional scenarios. These setups detect more than the compact 3-in-1 meters like the Mito Meter. That said, many professionals like using the Mito Meter as a person meter to save lugging around their professional gear when not working.

Where Does the Mito Meter Fit?

For someone like my daughter in her twenties, who’s only mildly sensitive to EMF and has no interest in buying a collection of bulky expensive meters, the Mito Meter is ideal. It helps manage weekly exposures on the move and is great for house hunting.

It’s a ±6 dB broadband RF meter that is slower than the Safe & Sound Pro II and under-reads in highly congested areas (as many meters do), but the audio signature mode still clearly identifies hot spots — especially above 1 µW/m².

While its RF sound isn’t as refined or sensitive as the Safe & Sound Pro II, Gigahertz Solutions, or Spion 5G, it does cover electric and magnetic field detection from 40 Hz to 50 kHz,* which the Safe & Sound Pro II does not. This makes the Mito Meter a powerful, affordable, all-in-one personal screening meter.

Final Thoughts

Choosing an EMF meter comes down to your:

• Budget

• Sensitivity

• Location and travel needs

• Planned usage

• Tech confidence

If you’re unsure, consult a reputable EMF professional in your area before buying, as they know which meters cover the frequencies in your area. Most consultants can provide discount codes, so the initial consult fee is often well worth it.

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Footnote: RF Spectrum Analyzer

Fast broadband meters like the Safe & Sound Pro II are excellent, but the gold standard in RF engineering is real-time spectrum analysis. This captures all frequencies within the analyzer’s range simultaneously, revealing signals within signals, which is critical for investigative and legal work.

*Magnetic mode detects from 40 Hz to 50 kHz and electric field mode from 40 Hz to 10 kHz.