Diving equipment includes a compressed air bottle connected to a breathing apparatus and an inflatable jacket via which buoyancy is balanced by the jacket being connected to the compressed air bottle to be inflated or to an outlet to be deflated. A monitoring device is activated via a control valve as a function of surrounding water pressure and has a time monitoring unit which, after the expiry of a defined time and in the absence of breathing activity in the breathing apparatus, changes to emergency operation and activates an emergency valve via a control line connecting the jacket to the compressed air bottle to force inflation of the jacket. Actuation of at least one regulating valve is influenced during a dive by the monitoring device and/or the control valve. In manual activation, the jacket is inflated via the inflation valve, and the compressed air is bled via the outlet valve.

Diving equipment includes a compressed air bottle connected to a breathing apparatus and an inflatable jacket via which buoyancy is balanced by the jacket being connected to the compressed air bottle to be inflated or to an outlet to be deflated. A monitoring device is activated via a control valve as a function of surrounding water pressure and has a time monitoring unit which, after the expiry of a defined time and in the absence of breathing activity in the breathing apparatus, changes to emergency operation and activates an emergency valve via a control line connecting the jacket to the compressed air bottle to force inflation of the jacket. Actuation of at least one regulating valve is influenced during a dive by the monitoring device and/or the control valve. In manual activation, the jacket is inflated via the inflation valve, and the compressed air is bled via the outlet valve.

Oxygen-delivery systems are described. The systems may supply emergency respiratory gas on demand to aircraft passengers. To reduce risk of blockage of tubes delivering anti-blocking gas to the face masks worn by the passengers, the systems may be designed to provide a continuous trickle flow of respiratory gas, or one or more anti-blocking pulses of gas, into a delivery tube.

Oxygen-delivery systems are described. The systems may supply emergency respiratory gas on demand to aircraft passengers. To reduce risk of blockage of tubes delivering anti-blocking gas to the face masks worn by the passengers, the systems may be designed to provide a continuous trickle flow of respiratory gas, or one or more anti-blocking pulses of gas, into a delivery tube.

A method for determining a characteristic such as partial pressure or percentage of a gaseous constituent in a first gas mixture flow in a flow chamber in which there is alternating flow in opposite directions between the first gas mixture flow and a second gas mixture flow. The steps may include a) introducing the first gas mixture flow into a sensing chamber when the first gas mixture flow flows in the flow chamber, b) preventing introduction of gas from the flow chamber into the sensing chamber at least when the second gas mixture flow flows in the flow chamber, c) sensing the characteristic of the first gas mixture flow in the sensing chamber.

A method for determining a characteristic such as partial pressure or percentage of a gaseous constituent in a first gas mixture flow in a flow chamber in which there is alternating flow in opposite directions between the first gas mixture flow and a second gas mixture flow. The steps may include a) introducing the first gas mixture flow into a sensing chamber when the first gas mixture flow flows in the flow chamber, b) preventing introduction of gas from the flow chamber into the sensing chamber at least when the second gas mixture flow flows in the flow chamber, c) sensing the characteristic of the first gas mixture flow in the sensing chamber.

Apparatus and associated methods relate to determining a fit-quality metric for a mask/face combination based upon a calculated dead-space volume between a virtual mask and a virtual face virtually aligned so as to create an integrity seal circumscribing a mouth and nose region. In an illustrative embodiment, an interactive virtual fitting system may receive a three-dimensional (3D) virtual face associated with a person. The system may retrieve 3D models of various respirators selected by user determined criteria. The system may then compute a fit-quality metric for each of the retrieved 3D models. The potential wearer may then be presented with the metrics for review. The potential wearer may select a respirator based upon these computed metrics. A virtual fitting of many respirators may advantageously reduce the time needed for selecting a properly fitting respirator while simultaneously ensuring that the selected respirator may be comfortable and well fitting.

Apparatus and associated methods relate to determining a fit-quality metric for a mask/face combination based upon a calculated dead-space volume between a virtual mask and a virtual face virtually aligned so as to create an integrity seal circumscribing a mouth and nose region. In an illustrative embodiment, an interactive virtual fitting system may receive a three-dimensional (3D) virtual face associated with a person. The system may retrieve 3D models of various respirators selected by user determined criteria. The system may then compute a fit-quality metric for each of the retrieved 3D models. The potential wearer may then be presented with the metrics for review. The potential wearer may select a respirator based upon these computed metrics. A virtual fitting of many respirators may advantageously reduce the time needed for selecting a properly fitting respirator while simultaneously ensuring that the selected respirator may be comfortable and well fitting.

A fastening unit, in particular a fastening unit for modules which are intended to supply a user of a breathing mask or breathing hood with breathable air, and to such modules. The fastening unit is designed to secure one module relative to another module, and has a first component part for assembly with the other module and a second component part for assembly with the module. The second component part is rotatable, by means of the first component part, about a predetermined angle relative to the first component part; and first and second subcomponents within the region of the defined angle can engage with each other in a plurality of positions.

A fastening unit, in particular a fastening unit for modules which are intended to supply a user of a breathing mask or breathing hood with breathable air, and to such modules. The fastening unit is designed to secure one module relative to another module, and has a first component part for assembly with the other module and a second component part for assembly with the module. The second component part is rotatable, by means of the first component part, about a predetermined angle relative to the first component part; and first and second subcomponents within the region of the defined angle can engage with each other in a plurality of positions.