Your Home EMF Measurement Guide
Written for first-time testers. Each section tells you which meter to use, which mode to set, where to stand, what the numbers mean, and how to record the result. Take your time — a good measurement session is unhurried.
Before You Start: Safety and Basics
- Never open electrical panels, meter bases, or any equipment with a cover. Everything in this guide is measured with equipment closed and sealed. Panels and meters carry full service voltage — they are not for DIY measurement.
- Measure where you actually are. The point of the test is the environment you live in, not the strongest number you can find by pressing a meter against a wall.
- Photograph every reading. A photo of the meter display (with the mode visible) plus a photo of the location is the single most useful thing you can submit.
- Note the conditions. Which devices were on, what time of day, doors open or closed. Sources change behavior, and context is what makes a reading interpretable.
Important: different meters measure different physical quantities. A milligauss (magnetic), a mV/m (electric), a mW/cm² (RF power), and a GS (dirty electricity) are not interchangeable, and readings cannot be compared across instruments or units without considering the meter, its mode, the distance, and the conditions. Do not worry about "beating" a number — record it accurately and we will interpret it.
1. Radiofrequency (RF) Measurements
Meter: Safe and Sound Pro II, LATNEX AF-3500, or the RF channel of a multi-field meter (TriField TF2 / GQ EMF-390). Mode: RF / microwave, peak (max-hold).
Why peak-hold and long windows
Most wireless sources transmit in short bursts — a Wi-Fi router pings periodically, a smart meter reports on a schedule, cell signals vary with traffic. A ten-second measurement will usually read near zero and tell you nothing. Set peak-hold and leave the meter running for 30–60 minutes at each location.
Where to measure
- Bedrooms — at the pillow position and at the center of the bed, plus one spot 1 m from each wall.
- Home office / workstations — at the chair, head height, facing the direction you work.
- Living areas — where you sit most, head height.
- At your router or mesh nodes — about 30 cm (1 ft) from the unit, and again at 1 m and 3 m. Note whether it is actively in use.
- Smart meter, outside — stand on your property at 30 cm, 1 m, and 3 m from the enclosure. Do not touch or open the meter. Run the long window to catch transmission bursts.
- Windows facing a cell tower or TDD antenna — if one is visible, measure at the window and 3 m inside from it.
What the numbers mean
RF meters display power density (mW/cm²) or field strength (mV/m). Typical quiet-room values are well under 1 mW/m². The FCC general-public reference limit at these frequencies is 1.0 mW/cm² (10 W/m²) — orders of magnitude above normal home values. Being far below the ceiling is expected; the useful question is how your rooms compare to each other and to a quiet reference room.
How to record
- Location (room, position), date, and start time of the window
- The peak value the meter settled on, with its units
- Devices on or off (especially your own Wi-Fi — toggling it off is the fastest way to identify your router's contribution)
- A photo of the display and a photo of the position
2. Magnetic Field Measurements
Meter: TriField TF2, GQ EMF-390, or HF-35C (magnetic mode). Mode: magnetic field, 60 Hz, peak-hold. Units: milligauss (mG) or microtesla (µT) — 1 mG = 0.1 µT.
Where to measure
- Bedrooms — pillow position, center of bed, and foot of bed. Magnetic fields from wiring and appliances fall off quickly with distance, so the bed position is what matters most.
- Living spaces and workstations — where you sit for long periods.
- Appliances — refrigerator, water heater, HVAC equipment, space heaters: measure about 30 cm from the unit with it running, and again at 1 m.
- Electrical panel vicinity — stand about 1 m from the closed panel. Do not open it.
- Transformers — if a utility transformer is near your home, measure outside at 1 m and 3 m from it, and inside the nearest room.
- One quiet reference room — a room away from wiring and appliances, for comparison.
What the numbers mean
Magnetic fields are produced by current flow and decrease rapidly with distance (roughly the cube of distance for a line source). Typical home background is under 1 mG; values of a few mG near appliances or wiring are common; sustained values above ~20 mG in a sleeping position are where people usually want to look closer. There is no universally accepted health threshold — we interpret your numbers in context, not against a single magic line.
How to record
- Position (e.g. "bedroom, pillow, head of bed"), date
- Peak value with units, and what was running (appliances, HVAC, neighbors' usage matters less than your own wiring)
- Photo of the display and the position
3. Electric Field Measurements
Meter: TriField TF2, GQ EMF-390, or HF-35C (electric mode). Mode: electric field, 60 Hz, peak-hold. Units: millivolts per meter (mV/m).
Where to measure
- Beds and sleeping areas — pillow position and center of bed. Electric fields are easily blocked by ordinary materials (a mattress, a person, furniture), so measure at the position you actually occupy.
- Office workstations — at the chair, and note the position of your desk relative to walls with wiring.
- Wiring in walls — sweep the meter slowly along a wall at about 30 cm; peaks near outlets and switches indicate wiring paths. This is normal — the question is whether occupied positions sit on those paths.
- Electrical devices — lamps, chargers, and electronics about 30 cm away, on and off.
What the numbers mean
Electric fields come from voltage, not current, so they exist even with nothing plugged in, and they are easily shielded. Typical occupied positions are in the low tens of mV/m; values in the hundreds near active wiring are common. As with magnetic fields, there is no single accepted threshold — context and distance are what matter, and electric fields are the easiest category to reduce (distance, grounding of large objects, or rearranging).
How to record
- Position, date, and what was plugged in / switched on nearby
- Peak value with units
- Photo of the display and the position
4. Dirty Electricity (Microsurge) Measurements
Meter: Stetzerizer Microsurge Meter (or equivalent). Mode: standard GS scale. Units: GS (0–100).
What this actually measures
Dirty electricity is high-frequency voltage noise on your building's wiring. It is measured at the outlet — plugged directly in — not in the air. Different outlets in the same room can read differently, so measure the outlets you actually use.
Where to measure
- Bedroom outlets — every outlet within ~3 m of the bed. Note which side of the bed each is on.
- Office / workstation outlets — the outlets your equipment plugs into.
- Kitchen and living-room outlets — a representative sample, especially near power electronics.
- Near specific suspects — outlets feeding LED drivers, smart plugs, solar inverters, or other electronics you are curious about.
How to read the GS scale
The meter shows a 0–100 GS scale with a needle or bar. As a working convention: readings in the lower part of the scale are unremarkable; the middle range is where filters are commonly considered; the upper range indicates significant noise on that circuit. The exact number is less important than the pattern — which outlets read high, and whether it changes when you unplug devices. Record the reading with the device plugged in and again with it unplugged; the difference tells you what that device contributes.
How to record
- Outlet location (room + position, e.g. "bedroom, left of bed")
- GS reading with devices on, and with the suspect device unplugged
- What is plugged into that outlet / circuit
- A photo of the meter at the outlet
Meter-specific limitation: the microsurge meter reads the wiring at the plug only. It says nothing about fields in the air, and readings vary by outlet even within one room.
Printable Measurement Worksheet
Print this page (or use your browser's Print → Save as PDF) and work through it room by room. Bring it to your consultation, or type your readings directly into your dashboard.
ClearEMF — EMF Measurement Worksheet
| Customer reference | Date | ||
| Name | Property |
| Room / location | Meter used | Type (RF / mag / elec / dirty) | Reading | Units | Distance from source | Device conditions | Notes |
|---|---|---|---|---|---|---|---|
Record the peak (max-hold) value. Note the time of day and which devices were on. Photograph each meter reading. Different meters measure different quantities — do not compare across units.