​Around the globe, natural gas consumption is rising steadily, making continuous monitoring of aging natural gas distribution infrastructures a crucial issue. The EU Redfinch project consortium is developing compact, sensitive, and fast photoacoustic sensors to replace the costly and time-consuming process of manually inspecting pipework with portable sensors.

The innovative sensors under development are built on a technique called photoacoustic spectroscopy, which measures the amount of light absorbed by the molecules of interest and the resulting acoustic waves. CEA-Leti developed a miniature photoacoustic cell, assembling a quantum cascade laser (QCL) source and a photonic integrated circuit (PIC). The device offers the advantages of low power consumption during operation (less than 10 W), making them suitable for continuous monitoring scenarios.

Compared to the conventional sensors currently in use, the innovative sensors developed here are effective on very small amounts of gas (1.6 ml) and are more sensitive (500 ppb). They are also better able to discern specific molecules and offer a wider dynamic range. Finally, they are more reliable and emit fewer nuisance alarms. These affordable, low-power sensors are designed to be integrated into wireless real-time infrastructure monitoring networks in refineries and other similar facilities.