RF room survey

Goal

Establish the peak and time-averaged RF power density at the positions people actually occupy, and identify the dominant source.

Equipment

• Broadband RF power-density meter
• Directional antenna (log-periodic or horn)
• RF spectrum analyser

Procedure

1. Record the meter make, model, frequency range and last calibration date; every reading is meaningless without them.
2. Note which transmitters are in the room and leave them in their normal state — do not switch things off yet.
3. Set the meter to peak-hold and walk the room slowly, holding the antenna away from your body at head height.
4. Record the maximum found, then take fixed readings at the pillow, the desk chair and the sofa position, 30 seconds each in peak-hold.
5. Repeat those fixed readings in average mode; report both numbers, since limits are averaged and consumer discussion quotes peaks.
6. Rotate slowly at the highest reading to find the direction of arrival, using a directional antenna if available, and note the bearing.
7. Switch off internal transmitters one at a time (router, DECT base, cameras) and re-read to separate internal from external contributions.
8. Record date, time of day, and weather; outdoor levels vary with network load and propagation.

Pitfalls

• Reporting a peak-hold number as if it were an exposure level comparable to a regulatory limit — limits are time-averaged
• Holding the meter against the body, which blocks and reflects the field
• Using a meter whose lower frequency limit excludes the band you care about, and concluding there is nothing there
• Surveying once, at one time of day, and treating it as the household's exposure
• Not identifying whether the dominant source is inside the building, which determines whether shielding can help at all

Interpret results against

• FCC general population MPE, 1.5–100 GHz
• ICNIRP 2020 general public reference level, 2–300 GHz
• Building Biology SBM-2024 RF band: no anomaly
• Swiss installation limit value for mobile phone antennas

Related records

• Wi-Fi router (2.4 / 5 / 6 GHz)

  A consumer access point radiating roughly 100 mW EIRP per band, giving about 8,000 µW/m² at 1 m and 80 µW/m² at 10 m in free space.

  Sources & emitters

• Broadband RF power-density meter

  The general-purpose instrument for Wi-Fi, cellular, 5G, smart meters and cordless phones: reports total power density across a wide band in µW/m² or mW/m², with peak-hold and average modes.

  Instruments

Sources

1. sbm-2024 Building Biology Evaluation Guidelines for Sleeping Areas (SBM-2024) — Institut für Baubiologie + Nachhaltigkeit (IBN), 2024. ngo, link checked 2026-08-12.
2. fcc-oet65 OET Bulletin 65: Evaluating Compliance with FCC Guidelines for Human Exposure to Radiofrequency Electromagnetic Fields — Federal Communications Commission, Office of Engineering and Technology, 1997. government, link checked 2026-08-12.
3. arpansa-base-stations Mobile phone base stations and health — Australian Radiation Protection and Nuclear Safety Agency. government, link checked 2026-08-12.