How to Test EMF Levels in Your House (Step-by-Step Guide 2025)
Testing your home's EMF levels is the most important step you can take before purchasing any protection products — and it is far simpler than most people expect. Without a baseline measurement, you are essentially spending money on solutions without knowing whether you have a problem, where it is coming from, or how severe it is. This step-by-step guide walks you through a complete home EMF survey from start to finish: which meters to use, what to measure, how to interpret your readings, and what to do with the results. No technical background required.
What You Are Actually Measuring
A home EMF survey covers three distinct field types, each requiring different equipment and measurement approaches. RF (Radio Frequency) radiation — from Wi-Fi, 5G, smart meters, phones — is measured in µW/m² (microwatts per square metre) or mW/m². ELF Magnetic fields — from power lines, wiring, transformers, appliances — are measured in mG (milligauss) or µT (microtesla). ELF Electric fields — from in-wall wiring, extension cords, lamps — are measured in V/m (volts per metre). Each type has different health guidelines, different sources, and different mitigation strategies. Measuring all three gives you a complete picture of your home environment.
Reference Levels: What Do the Numbers Mean?
RF Radiation (Building Biology IBE Guidelines):
ELF Magnetic Fields:
Step-by-Step Home EMF Testing Guide
Choose and Prepare Your Meters
Recommended Meter Setup
Best All-in-One: TriField TF2 (~$180) — RF + ELF magnetic + ELF electric
Budget Start: Meterk MK54 (~$35, ELF only) + Safe and Sound Classic (~$100, RF only)
Professional: TriField TF2 + Acoustimeter AM-11 combination
For most homeowners, the TriField TF2 is the ideal single device — it measures all three EMF field types with one unit and is the most trusted consumer meter globally. Before starting your survey, familiarise yourself with the meter's three measurement modes: RF (for wireless radiation), magnetic (for ELF magnetic fields from appliances and wiring), and electric (for ELF electric fields from in-wall wiring). Read the manual's section on units and ranges so you understand what the numbers mean before you begin. Keep a notepad or open a spreadsheet to record every reading with the room, location, and device conditions at time of measurement.
Establish Baseline Conditions Before You Start
Why Baseline Conditions Matter
Rule: Measure with all devices in their normal operational state
Document: Which devices are on, which are off, time of day
Repeat later: Test same spots with devices off to isolate sources
Your first survey pass should capture real-world exposure levels — Wi-Fi on, phone active, smart devices plugged in, appliances in normal use. This is your true baseline. Record each reading with the exact location (e.g. "bedroom — pillow position — 60cm from router wall"), the device state, and the time. A second pass with all devices switched off and Wi-Fi disabled reveals your "background" level — the irreducible external sources (neighbours' Wi-Fi, 5G towers, smart meters) you cannot control directly. The difference between these two readings tells you how much of your exposure is self-generated and therefore reducible.
Survey the Bedroom First (Priority Room)
Bedroom Measurement Points
Position 1: Pillow height — most critical reading
Position 2: Each exterior wall (facing outside)
Position 3: Near any powered device (clock, phone charger, TV)
Stand at pillow height with your RF meter and rotate slowly to find the direction of highest readings — this identifies your dominant source direction and helps prioritise shielding placement. Measure RF at each exterior wall and record the highest value per wall. Then switch to ELF magnetic mode and walk slowly around the room — ELF hotspots show up as sudden spikes near the bed frame, clock radio, phone charger, or electrical panel on the other side of the wall. Finally, measure ELF electric fields by holding the meter near in-wall sockets and along the skirting board — high readings here indicate unshielded wiring carrying significant current near the sleeping area.
Survey the Home Office / Living Areas
Key Measurement Points
Desk position: At seated head height and lap height
Router: At 0.5m, 1m, 2m, 3m distances
All four directions from your desk chair
At your desk, measure RF at seated head height from all four directions — front (towards monitor and router), back, left, and right. This identifies which direction the dominant signal comes from. Then measure ELF at lap height to capture laptop and power adapter ELF output. For the router, take systematic readings at 0.5m, 1m, 2m, and 3m and plot the gradient — this data helps you determine the minimum safe working distance and justifies relocating either your desk or the router. In the living room, measure near the TV, any smart speakers, and the cable/satellite box — these are often overlooked moderate ELF sources.
Locate and Measure Your Smart Meter
Smart Meter Survey Protocol
Outside: Measure at 0.5m, 1m, 3m from the meter box
Inside: Measure on the interior wall directly behind the meter
Adjacent rooms: Check all rooms sharing or near the meter wall
Walk outside your home and locate the smart meter box — typically mounted on an exterior wall. Hold your RF meter at 0.5m, 1m, and 3m and record the reading each time you see the meter pulse (the reading will spike every 15–30 seconds). Then go inside and find the interior wall directly behind where the smart meter is mounted outside. Measure here — many homeowners are surprised to find RF levels well above 1,000 µW/m² on the interior surface of their meter wall. Check all rooms that share or adjoin this wall, especially any sleeping areas or children's rooms. This data prioritises where shielding paint or a meter guard is most needed.
Test Every Major Appliance for ELF Output
Appliance ELF Testing Protocol
Method: Hold ELF meter at 5cm, 30cm, and 1m from each appliance
Record: Distance at which reading drops below 1 mG
Priority appliances: Microwave, fridge, electric cooker, washing machine
Switch each appliance on and hold your ELF meter at 5cm, then step back to 30cm, then 1m, recording the reading at each distance. Note the distance at which the reading drops below 1 mG (your safe daytime threshold) — this is your safe zone distance for that appliance. Most users are surprised by how quickly ELF drops with distance — a microwave that reads 200 mG at 5cm may read only 2 mG at 1m. The key priority appliances to test are: microwave oven, refrigerator (compressor side), electric cooker, washing machine, dishwasher, electric fan heater, and any device with a large transformer or motor. Note which appliances are near areas where you spend extended time.
Check External Sources: 5G Towers & Neighbours' Wi-Fi
External Source Survey
Method: Measure RF at each window and exterior door
Tool: Use audio mode if available to identify pulsed signals
Record: Direction and signal type for each elevated reading
Stand at each window and exterior door and take RF readings while pointing the meter outward. Higher readings from specific windows indicate external sources — 5G towers, neighbours' routers, or cellular base stations in that direction. If your meter has an audio output (Acoustimeter, Safe and Sound Pro), listen to the demodulated signal — 5G NR produces a characteristic pulsed pattern distinct from Wi-Fi or 4G LTE. These external sources cannot be turned off, but can be addressed with EMF shielding curtains, window film, or shielding paint applied to the relevant exterior wall. Mapping external sources by direction helps you prioritise where to install shielding most cost-effectively.
Verify Shielding Product Effectiveness
Before-and-After Testing Protocol
Step 1: Record baseline reading at exact measurement point
Step 2: Install shielding product (case, blanket, paint, curtain)
Step 3: Re-measure at identical position and device conditions
Every shielding product you purchase should be verified with a before-and-after measurement. Use the same meter, at the exact same position, with the same devices operating at the same state. Calculate your reduction percentage: (Before - After) ÷ Before × 100 = % Reduction. For example, if your bedroom pillow showed 2,500 µW/m² before and 25 µW/m² after installing a shielding blanket and switching off your router, that is a 99% reduction. This data confirms your investment is working and also protects you as a consumer — if a shielding product shows no measurable improvement, it is not performing as advertised.
EMF Reading Interpretation Reference Table
| Field Type | Unit | No Concern | Moderate Concern | Severe Concern | Common Source at Severe |
|---|---|---|---|---|---|
| RF Radiation | µW/m² | <0.1 | 10–1,000 | >1,000 | Smart meter, Wi-Fi router, 5G |
| ELF Magnetic | mG | <0.2 | 1–5 | >5 | Power lines, electric motors, wiring |
| ELF Electric | V/m | <1 | 5–50 | >50 | Unshielded wiring, extension cords |
| RF (FCC Limit) | µW/m² | 10,000,000 (regulatory max — not a health guideline) | — | ||
Typical Home Readings: What to Expect
Typical RF Readings in an Unshielded Home
Important: Regulatory Limits vs. Health Guidelines
FCC and ICNIRP regulatory limits for RF exposure are set orders of magnitude above Building Biology health guidelines. This is because regulatory limits are designed to prevent acute thermal injury from short-term high-intensity exposure — not chronic low-level biological effects from sustained daily exposure. A reading of 5,000 µW/m² is well below the FCC limit but 50,000 times higher than the Building Biology "no concern" threshold. Use Building Biology guidelines as your target — not regulatory limits — when assessing your home's safety.
Documenting and Acting on Your Results
Your Post-Survey Action Plan
Create a Room-by-Room EMF Map
Draw a simple floor plan and mark each measurement point with its reading and field type. Use colour coding — green for safe, amber for moderate, red for severe. This visual map makes it immediately clear which rooms and which sources need priority attention.
Prioritise by Time Spent × Exposure Level
Multiply the severity of the reading by how many hours per day you spend in that location. A moderate reading in a room where you sleep 8 hours is more important than a severe reading in a hallway you pass through twice a day. Focus your efforts on the highest-impact combination of duration and intensity.
Separate Self-Generated from External Sources
Your second survey pass with all devices off tells you your background level from external sources. If this is already high (e.g. dense urban 5G environment), prioritise structural shielding. If it is low, focus on eliminating your own devices as the primary solution.
Implement Changes in Priority Order
Start with free actions (switching off Wi-Fi at night, removing phone from bedroom, repositioning bed) and verify each change with your meter before spending on products. Only purchase shielding products after confirming that free measures alone are insufficient to reach your target levels.
Re-Survey Every 6–12 Months
Your EMF environment changes over time as new 5G infrastructure is deployed, neighbours change their devices, and your own household gadgets are added or replaced. An annual survey ensures your protection measures remain adequate and helps you detect new sources before they become a long-term exposure problem.
Common Mistakes to Avoid When Testing
1. Testing with devices off: Always start with everything in normal operation — this is your real exposure.
2. Forgetting peak vs. average: Smart meters and Wi-Fi pulse intermittently — watch for peak readings, not just the average. Stay in each location for at least 60 seconds.
3. Testing only one room: EMF sources in adjacent rooms, above, and below can contribute significantly to any room's reading.
4. Ignoring ELF: Most people only test RF. ELF from wiring and appliances can exceed safe levels even in homes with no wireless devices.
5. Not recording exact positions: Without noting exactly where you measured, you cannot replicate the test for before/after comparison. Use a tape measure if needed.
Conclusion
A thorough home EMF survey takes 1–2 hours and transforms your understanding of your electromagnetic environment. Rather than making purchases based on general anxiety about EMF, you can make targeted, evidence-based decisions about which sources to address, in which rooms, and in what order. The TriField TF2 provides everything a homeowner needs for a comprehensive survey of all three field types.
The most important insight most people take from their first home survey: the largest sources of exposure are almost always self-generated and immediately reducible — the phone on the nightstand, the Wi-Fi router running 24/7, the wireless devices left active overnight. These cost nothing to address and deliver the largest reductions. Start there, verify with your meter, and work outward from that foundation.
When to Call a Professional Building Biologist
If your survey reveals severe RF readings (>10,000 µW/m²) from sources you cannot identify, or ELF magnetic readings consistently above 5 mG throughout the home, consider hiring a certified Building Biologist (IBE or BBE certified) for a professional assessment. They can use calibrated professional-grade instruments, identify sources inside walls and from utilities, and provide a comprehensive remediation report. Look for IBE (Institut für Baubiologie) or BBEC (Building Biology Environmental Consultant) certified practitioners in your area.
