If you have a Ship’s Radio Licence then you may have received an email from Ofcom recently regarding new compliance rules on EMF (electromagnetic field) exposure. The International Commission for Non-Ionising Radiation Protection (ICNIRP) aims to protect people and the environment against adverse effects of non-ionizing radiation – that includes signals from radio transmitters. Some Digital Yacht products especially AIS transponders fall into this category so you may find this article helpful and we hope it alleviates any concerns you may have.
From the 18th of May 2021, boat owners may have to assess the safety of their radio transmissions. The new proposed conditions only apply to wireless equipment that can transmit at power levels above 10 Watts EIRP (or 6.1 Watts ERP). Licence holders will be given a grace period of at least 6 months to comply. The good news is that Class B & Class B+ AIS products only transmit with a 2 and 5W power output so don’t require an assessment.
For those transmitters that transmit above this level (this could include VHF and Class A AIS), the installation will need to be assessed to ensure compliance with the new Ofcom requirements. Ofcom have provided a calculator (spreadsheet) to assist in calculating the Electromagnetic Field (EMF) of an installation. A copy of the proposed calculator can be found on Ofcom’s webpage HERE
The calculation is straight forward – you just need to enter your transmitting frequency (156MHz for marine VHF and 162MHz for AIS) and your transmitter power (12.5W for a Class A AIS)
The calculator will then give you the safe distance from the antenna which for a Class A AIS works out as 1.13m. This distance is further mitigated by the duty cycle of the transmission which is just a fraction of a second for an AIS transmission so the reality is a human can stand adjacent to an AIS antenna without issue
For those interested there is a Ofcom compliance document HERE