Abstract: A sealing valve is provided for a sensor that includes a sensing element and a sensor opening that exposes the sensing element. The sealing valve includes a housing that is configured to be mounted to the sensor such that an internal channel of the housing fluidly communicates with the sensor opening. The sealing valve includes a float element configured to float along a surface of the liquid. The float element is configured to move within the internal channel between an open position and a closed position. The float element is configured to close the sensor opening to the internal channel in the closed position. The sensor opening is open to the internal channel when the float element is in the open position. The float element is configured to rise with the surface of the liquid within the internal channel toward the closed position.

Abstract: An electrochemical gas sensor biasing module may include a main housing, a battery that is contained in and/or extending from the main housing, and a sensor connector extending from a portion of the main housing. The sensor connector is configured to removably connect to an electrochemical gas sensor so that energy from the battery is delivered to the electrochemical gas sensor in order to maintain the electrochemical gas sensor in a biased state.

Abstract: In an alarm network involving a set of intercommunicating alarm nodes, departure from the network of the master node—due to failure, in the course of system reconfiguration, or for some other reason—is detected by the remaining nodes in the network, which cooperate to elect or designate a new master node autonomously.