A sensing device arrangement for a fuel storage system is provided having at least one storage tank, a plurality of sensing devices positioned in or around the at least one storage tank, and a controller in electrical communication with the plurality of sensing devices. The controller is configured to communicate with each sensing device of the plurality of sensing devices on a single bi-directional data line. A sensing device of the plurality of sensing devices is activated by the controller. Data is acquired by the sensing device and transmitted to the controller over the data line. The controller instructs the sensing device to change to a low power state. The controller receives electrical characteristics from the plurality of sensing devices recognized on the data line and calculates a characteristic of the sensing device arrangement. The controller verifies compliance with an intrinsic safety barrier.