A leading manufacturer in the railway sector contacted us for help at testing its system according to ETSI EN 300 330 V2.1.1:2017 regulation. This is not a norm to be tested with usual EMC procedures, as it refers to radio communications equipment using inductive loops in the 9 kHz – 30 MHz range.
Inductive loops are infrastructure-carriage communications systems based on magnetic fields used to detect when coaches pass over them.
Essays for the specific regulation requested in this occasion was not included in our usual services, but our lab is at the disposal of our customers, so we decided to adapt our resources to the process needed and accepted the challenge. We wouldn’t like to let our customers down.
As this case was not one of the most ordinary projects we’ve developed in our lab, first of all we had to conduct a deep research task to analyze the norm thoroughly. Then we could proceed to the classification of the equipment in the categories described and the definition of the corresponding essays, as well as the presentation of the technical justification needed.
The second step was checking if all systems and equipment required to perform these essays were available in our lab or an additional equipment rental would be needed. But we had an additional request added to the first project proposal: the magnetic fields should be analyzed also from a safety perspective, having into account possible effects on people with pacemakers walking around the inductive loop.
To ensure this point, the UNE-EN IEC 62311 norm had to be inspected and measurements according to UNEP/WHO/IRPA 1993 recommendation had to be performed. To do so, we had to rent specific equipment to an external partner and, in search for quality, we chose an internationally acclaimed provider.
Once the required essays and procedures were established, we had to create specific accessories, such a purpose-designed support to maintain the loop in a vertical position, as the norm states, with a wire to be buried underground.
During the essay process, measurement actions and methods were created following the norm criteria. Limitations were identified and results justified.
After the technical part, it was time to deal with formalities. As the project is about a communications system, the government of the country in question had to review and approve its usage. It was then when we discovered that the band used was not allowed in the country, but it was included in the ETSI EN 300 330 V2.1.1:2017 norm though. We had to execute an additional work to justify the use of this band taking recommendations by ETSI (European Telecommunications Standards Institute). Following this extra effort, our customer’s system was authorized.