Getting the Data
Obtaining accurate measurements of RF radiation in a classroom is not a simple task. Readings (and radiation exposure) can be affected by building materials, the presence of metal or other reflective objects, the number of devices in use, etc.
Note: If the school permits students to have cell phones in class, reading should be taken with all cell phones on and again with all cell phones off.
Peak vs. Average Exposures
The parameter used by the FCC to determine exposure limitations for humans is time-averaged Specific Absorption Rate (SAR). However, time-averaging is not how the body experiences the effects of RF radiation. In fact, this measurement method actually obscures the unique characteristics of intensity-modulated (pulsed) RF radiation that many scientists believe is responsible for causing biological harm.
Measuring RF Radiation
The following mitigation techniques are designed to help you to reduce exposure to as low as reasonably achievable (ALARA). Step One is to know and understand what kind of exposures currently exist.
We recommend as a first step the consultation with a professional who is trained in measuring RF exposures. Typical cost for this professional service is $1200 to $2,000. We do not generally recommend asking vendors to perform this testing due to obvious conflicts of interest and lack of professional training.
As an alternative, school IT personnel can purchase or rent a professional grade RF meter to test exposures. There is a huge variation in the quality and reliability of meters used to conduct RF surveys. We strongly recommend one of the following meters to obtain accurate and meaningful measurements:
Safe and Sound Pro II
• Accurately reads both bands of Wi-Fi and cellular phones
• Rigorously tested in a lab, with published frequency response
• +/- 6dB accuracy from 400 MHz to 7.2 GHz; verified by a third party.
• Can detect signals from 200MHz to 8GHZ.
• New model introduced in October 2020. (Limited information available)
• 200 – 8 000 MHz ±6 dB ±0.02 V/m
• $385 USD
HFW59D Plus RF Meter Kit
• Most accurate meter to measure Wi-Fi but will not measure most cellular signals.
• Most accurate but costs more.
• 2.4 GHZ to 10 GHZ @ +/- 4.5dB
Basic Meter Operating Protocol
1. Wave the meter in figure 8 pattern while slowing rotating 360 degrees so that your body doesn't block any signal.
2. Keep the meter >1 foot away from metal, mirrors, or other reflective surfaces and all wireless devices.
3. Measure the average and peak (maximum) exposures and record data (V/m uW/m2)
Baseline Measurements - Step By Step
1. Turn off, unplug or disable all wireless devices, including WAPs and smartboards.
2. Remove or power down all laptops, tablets, computers, cell phones, wearables, Bluetooth speakers and other wireless devices as these may still be transmitting even if they are in standby or airplane mode.
3. Ensure all wireless devices and personal devices are off in neighboring classrooms including those located above, below or beside the classroom being measured.
A Word About
FCC Exposure Guidelines
The FCC's 24-year-old human exposure guidelines for RF radiation are based on an outdated understanding of how it impacts the human body, considering only heating of tissue, not the biological damage from non-thermal exposures documented in recent (2018) U. S. government studies and thousands of previous studies.
There are no standards of RF radiation exposure for children.
The FCC was successfully sued for failure to properly evaluate recent scientific studies documenting harm. Compliance with FCC guidelines is no guarantee of safety for children or a shield against potential legal liability for schools and their administrators.