Abstract: The gas monitoring system may include a gas line, an oxygen sensor, a filter, a pump, a indicator, and a controller. The gas line is configured to convey gas from a space configured to receive inert gas to a location remote from the space. The oxygen sensor is fluidly coupled to the gas line at the location. The oxygen sensor is configured to determine a partial pressure of oxygen present in the gas. The filter is fluidly coupled to the gas line between the space and the location. The filter is configured to remove combustible contaminants from the gas before it reaches the oxygen sensor. The controller is electrically coupled to the oxygen sensor and to the indicator. The controller is configured to activate the indicator when the partial pressure of oxygen exceeds a predetermined level.

Abstract: An aircraft refueling system incorporates a fuel port adapter configured to allow the use of jet fuel nozzle spout but prevent the use of avgas nozzle spout. The device has an opening that configured to receive a standard jet fuel nozzle spout. The device also includes a blocking plate that prevents a smaller, round standard avgas nozzle spout from being inserted into the opening. In addition, the device includes one or more spring-loaded flapping doors to prevent incorrect refueling while the jet fuel nozzle spout is not inserted through the flapping doors.

Abstract: The gas monitoring system may include a gas line, an oxygen sensor, a filter, a pump, a indicator, and a controller. The gas line is configured to convey gas from a space configured to receive inert gas to a location remote from the space. The oxygen sensor is fluidly coupled to the gas line at the location. The oxygen sensor is configured to determine a partial pressure of oxygen present in the gas. The filter is fluidly coupled to the gas line between the space and the location. The filter is configured to remove combustible contaminants from the gas before it reaches the oxygen sensor. The controller is electrically coupled to the oxygen sensor and to the indicator. The controller is configured to activate the indicator when the partial pressure of oxygen exceeds a predetermined level.