On a recent stroll through Hawaii Volcanoes National Park, [Andrew Cooper] stumbled upon an unlocked surveillance station. As an engineer, he couldn't help but look. This station is part of a network of sulfur dioxide (SO2) measuring stations installed around the park to keep an eye on volcanic emissions. Unsurprisingly, sulfur dioxide is unhealthy to breathe. Sensors like this inform people about the local conditions before they walk between the volcanic foothills and enjoy wonderful views [Andrew] describes it.
[Andrew] was not particularly surprised by the content of the station, as he builds similar devices in his daily work. Continuous energy is provided by lead-acid batteries that are charged by an array of three mismatched solar panels. At the top are double SO2 monitors, an air particle meter and a standard weather station. The data is logged on site and reported via a cellular modem in the chain. [Andrew] was not impressed with the workmanship and noted:
It seemed like the circuits were being wired by a clumsy graduate student who took no pride in his work.
Tracking atmospheric SO2 levels near volcanoes doesn't just help hikers and park rangers plan their outdoor activities. Gaseous emissions from volcanoes are one of several measurements that geologists rely on to monitor and predict volcanic activity, as this sketch from the USGS website shows.
Have you worked on projects with such unsupervised measuring stations or have you encountered them in the wild? [Andrew]? Let us know in the comments below.