Data Transmission from ATEX Boxes by Means of LoRa Technology for Industrial Internet of Things (IIoT) Applications

European Union Directive 2014/34/UE regulates characteristics of electronic devices operating in the so-called ATEX environments, i.e., environments featuring a high risk of explosions. Since in these cases electronic components must be separated from the environment itself, sealed metallic ATEX-compliant boxes have been realized to house any electronic component to operate within these scenarios. The aim of this paper is to demonstrate the feasibility of a LoRa transmission from inside an ATEX box to a Gateway positioned outside it. Indeed, LoRa, with the associated LoRaWAN protocol, is becoming day-by-day a crucial technology for the implementation of the so-called Industrial Internet of Things (IIoT) applications. Such a solution may easily overcome any problem of data transmission from inside to outside the box. Tests have been performed exploiting a real 2 cm thick aluminum ATEX box, analyzing radio parameters like Received Signal Strength Indicator (RSSI) and Signal to Noise Ratio (SNR). Results confirm the effectiveness of this transmission channel, while the measured link margin suggest the functioning of this technology also with LoRaWAN Gateway placed at higher distances from the ATEX box, thus fostering its use also in real industrial scenarios.