>>> Tests carried out from November 12 – 14 at Aix-en-Provence by David BRUNO (www.electromagnetic-expert.com) in the presence of representatives from Flex-a-ray

1// Principle of the Trial

> Measurements of electromagnetic radiation during PCL communications from Linky-type meters (from 35 Khz to 90 Khz) around non-shielded electrical sheathing (1 neutral wire and one phase wire inside)

> Measurements of electromagnetic radiation during PCL communications from Linky-type meters (from 35 Khz to 90 Khz) around shielded Flex-a-ray/Prefilzen electrical sheathing (1 neutral wire and 1 phase wire inside)

> Demonstrate the amount of attenuation of electromagnetic radiation emissions achieved during PCL communications from Linky-type meters (from 35 Khz to 90 Khz) when using Flex-a-ray/Prefilzen shielded sheathing

> Calculate the attenuation coefficiency of electromagnetic radiation during PCL communications from Linky-type meters (from 35 Khz to 90 Khz) obtained thanks to the use of Flex-a-Ray/Prefilzen sheathing.

It is important to note that around a live electric wire it is possible to measure not only a 50 Hz electric field of several hundred volts/meter but also radiation of around 1 volt/meter in the frequency band situated between 9 Khz and 32 Mhz. 

In reality, the electrical network is a gigantic antenna which radiates waves in Khz. This can be observed not only in the home but also under high-voltage power lines.

Trial Conditions

Trials were carried out in an apartment around a standard electrical sheathing installation and also near Flex-a-Ray/Prefilzen sheathing.

The tests presented are valid for PLC Linky-type G3 signals (the entire frequency band used between 35 Khz and 90 Khz).

In order to carry out tests in this apartment and to capture sufficient Linky communications, it was necessary to wait until 0H.10 (there are a large number between 0H.10 and 0H.40).  During daytime, PLC Linky communications were quite infrequent.


I have already noted nearly permanent important PLC Linky communications in several homes in Lyon, Toulon and several other towns essentially coming from PLC G1 meters.

Principle of measurement

The principle is to measure several Linky-type radiation values over a five-minute period (that often corresponds to around 20 communications), then to note the strongest values.

This series of five-minute measurements has been repeated for a total of nine times over three different test dates – three times on each date (12, 13 & 14 November 2019 between 0H.10 & 0H.40).

An average of the maximum values of the electromagnetic radiation measured has then been calculated for all the tests around the standard sheathing and all the tests around the Flex-a-Ray/Prefilzen sheathing.

Measuring apparatus used

For measuring the electric field radiated between 9 Khz and 300 Mhz, a NARDA SRM 3006 Spectrum Analyser with the probe 3531/04 was used (see probe calibration certificated in annex 1).

This is the exact same material as used by certified laboratories such as COFRAC (ANFR, EXEAM…).

2// Test results of Flex-A-Ray/Prefilzen sheathing during Linky PLC communications.

Comparison of radiation attenuation in Khz around both shielded and non-shielded sheathing during PLC Linky communications.

Measurements in Khz and Mhz bands around standard sheathing as well as around Flex-a-Ray shielded sheathing containing live wiring.

The indicated average over three series of 5-minute measurements carried out on three different dates.


We can clearly see an attenuation of around 10 of the radiation in the 35 Khz to 90 Khz frequency band during PLC Linky-type communications:  which represents enough attenuation to be protected from PLC Linky communications.

3// Attenuation test results from the Flex-a-Ray/Prefilzen sheathing outside of PLC Linky communications

Here below attenuation results of the “background noise” (outside of PLC communications) between 35 Khz & 90 Khz thanks to Flex-a-Ray/Prefilzen shielded sheathing:         

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