Safe and Sound Pro 2 Review: What This RF Meter Can and Can't Do

The Safe and Sound Pro II is a rechargeable handheld RF meter that measures radio-frequency signals from 200 MHz to 8 GHz, with its most accurate response between 400 MHz and 7.2 GHz. That covers the signals most people want to check at home: Wi-Fi, mobile phones and masts, cordless phones and smart meters. It isn't designed for low-frequency fields from wiring and appliances, and it doesn't reach the very high millimetre-wave 5G bands.

This review is for anyone comparing RF meters before buying. It covers what the Pro II measures, how accurate it is, how to read it, how to check your meter is working, and how it compares with the Classic III and EM3. If you're not sure what type of meter you need yet, read which EMF meter you need first.

Safe and Sound Pro II at a glance

• Type: RF (radio-frequency) meter
• Frequency range: 200 MHz to 8 GHz; true response 400 MHz to 7.2 GHz at ±6 dB
• Measuring range: 0.001 to 2,500,000 µW/m²
• Units: switchable between µW/m² and V/m
• Display: four-line OLED with bar graph
• Features: max hold with clear, audio signal analysis, adjustable volume, headphone socket
• Battery: built-in rechargeable, up to 24 hours per charge, charged by USB-C
• Made in: Canada/USA by Safe Living Technologies
• Warranty: 2 years

Safe and Sound Pro II frequency range: what it covers and what it misses

Most RF signals in a UK home sit comfortably inside the Pro II's range:

• Mobile phones and masts: 2G to 5G bands up to 3.8 GHz.
• Wi-Fi: routers, mesh points and devices at 2.4, 5 and 6 GHz.
• Cordless DECT phones and baby monitors.
• Smart meters and many smart-home hubs.
• Bluetooth devices such as earbuds and watches.

What it doesn't measure is just as important. First, low-frequency electric and magnetic fields from wiring, consumer units and appliances need a different instrument, such as the Safe and Sound EM3. Second, the highest 5G bands. In October 2025 Ofcom confirmed the results of its millimetre-wave auction, with EE, O2 and VodafoneThree each paying £13m for spectrum in the 26 GHz and 40 GHz bands. Those frequencies are aimed at very busy places, travel only short distances, and sit well above the 8 GHz limit of the Pro II and most consumer RF meters. For most homes the mid-band 5G signals below 4 GHz are still what you'll pick up, and the Pro II measures those.

Is the Safe and Sound Pro 2 accurate?

The Pro II is factory calibrated and temperature-compensated, with a stated accuracy of ±6 dB across its true response range. That figure is normal for broadband consumer RF meters, but it's worth understanding what it means. A 6 dB difference is a factor of four in power density (µW/m²) and a factor of two in field strength (V/m). So two good meters can show noticeably different numbers in the same spot.

In practice that makes the Pro II well suited to:

• Finding sources and hotspots in a room.
• Comparing before and after readings when you move a router or add shielding.
• Tracking whether levels change over time in the same position.

It isn't a certified instrument for formal compliance surveys, which use laboratory-calibrated spectrum analysers and antennas. The manufacturer publishes independent lab test results if you want to see how it was checked.

How to read the Safe and Sound Pro II

• µW/m² or V/m: µW/m² (power density) is the unit most home guides use and shows small changes more clearly. V/m (field strength) is common in official limits. Pick one and stick with it when you compare readings.
• Jumping numbers: many devices transmit in short bursts, so readings rise and fall from second to second. That's normal; watch the bar graph for the overall level and use max hold to catch the highest burst.
• Max hold: leave the meter in one spot, such as your pillow, and max hold keeps the highest reading. Clear it before each new test.
• Sound: each technology has its own sound pattern. Wi-Fi, mobile signals and smart meters sound distinct, which helps you work out which source you're hearing.

For a full room-by-room method, see our guide to finding radiation hotspots with an EMF detector.

How to test an EMF meter is working properly

You can't recalibrate a meter at home, but you can check it's responding sensibly:

• Router test: stand a metre from your Wi-Fi router, note the reading, then switch the router off. The reading should drop sharply.
• Phone test: hold the meter near your phone during a call or a large download, then switch the phone to aeroplane mode.
• Distance test: step back from a source. Readings should fall quickly as you move away.
• Repeat test: take readings in the same spot at the same time on different days. Similar numbers mean the meter is consistent.
• Second meter: if you have access to another RF meter, compare trends rather than exact numbers, given the ±6 dB tolerance.

If the meter doesn't respond to an obvious source, check the battery first, then contact us.

Safe and Sound Pro II vs Classic III vs EM3

• Classic III (£179): same 200 MHz to 8 GHz range with coloured lights and sound instead of a numeric display. Good for quick checks and finding sources; less useful for recording before and after numbers.
• Pro II (£349): adds a numeric display, unit choice and max hold. Best if you want to measure, record and compare.
• EM3 (£644): measures low-frequency electric and magnetic fields (50 Hz to 400 kHz), not RF. It complements an RF meter rather than replacing one.

Who is the Pro II for, and who should buy something else?

The Pro II suits people who want real numbers: anyone planning shielding, checking a bedroom, or testing whether a product actually reduces RF. If you only want to know whether a source is present, the Classic III is cheaper. If your main concern is wiring, electric blankets or appliances, start with a low-frequency meter. And if you want readings over time rather than spot checks, a wearable or logging monitor may suit you better.

Frequently asked questions

Does the Safe and Sound Pro II measure 5G?

Yes, for the 5G bands used by most UK networks below 4 GHz. It doesn't cover the 26 GHz and 40 GHz millimetre-wave bands.

Can the Pro II detect smart meters?

Yes. Smart meter transmissions fall within its range and have a recognisable sound pattern.

Does it measure electric fields from wiring?

No. Wiring and appliances produce low-frequency fields, which need a meter such as the EM3.

How long does the battery last?

Up to 24 hours of use per full charge, with charging by USB-C taking around 12 hours.

Is the Pro II worth it over the Classic III?

If you'll compare readings before and after changes, yes. For simple source-finding, the Classic III does the job for less.

Choose the right RF meter for your home

Decide whether you need numbers, alerts or low-frequency readings, then choose the meter to match. See the Safe and Sound Pro II, compare our EMF detectors, or ask us which meter fits what you want to measure.

This article describes measurement equipment and makes no health claims. Reducing exposure is a personal choice; UK and international health bodies do not consider harm established below international guidelines.