Abstract: There is provided a sensor including a housing, where the housing has an opening configured to receive a sensing element; an electric circuit operably connected to the housing, where the electric circuit is configured to detect at least one electrical characteristic across at least one pair of electrodes positioned on the sensing element; at least one gas-moving element in electrical communication with the electric circuit; and a reader in communication with the electric circuit, where the reader is configured to compare information about a gas volume external to the housing with information about a gas volume within the housing.

Abstract: A ring-shaped cushion for a hearing protector or audio headset. The cushion has a circumferential contact pad for sealing on a wearer's head and an attachment for sealing with an earmuff. The cushion further has a sound insulation tube that inwardly defines an inner space. The sound insulation tube extends between the contact pad and the attachment. The cushion has a ventilation passage that extends entirely through the cushion between an inlet opening in the contact pad and an area outside of the inner space. The cushion may further include one or more physiological sensors to monitor the health of a wearer.

Abstract: There is provided a fit testing method comprising: providing a respirator donned by a wearer; providing a sensor in electrical communication with a sensing element, where the sensor is configured to monitor a particulate concentration parameter of a gas space within the respirator, and a second particulate concentration parameter of a gas space outside the respirator, where the sensor is attached to the respirator such that the respirator such that the weight of the sensor is supported by the respirator; and providing a reader configured to communicate with the sensor, where the reader is configured to provide a respirator fit parameter based on a comparison of the particulate concentration within the respirator to the particulate concentration parameter outside the respirator.

Abstract: A method of fit testing includes providing a respirator donned by a wearer, providing an aerosol generator with a known aerosol output parameter, providing an enclosure that is physically supported around the wearer's head, where the aerosol generator delivers aerosol with the known aerosol output parameter that is at least partially contained within the enclosure around wearer's head, providing a sensor in electrical communication with a sensing element, where the sensor is operably connected to the respirator, and where the sensor is configured to monitor a particulate concentration parameter within the respirator, and providing a reader configured to communicate with the sensor, where the reader is configured to provide a respirator fit parameter based on a comparison of the particulate concentration parameter to the known aerosol output parameter.

Abstract: A system includes a respirator, a sensor including a sensing element, and a reader configured to be in wireless communication with the sensor. The sensor is positioned substantially within an interior gas space of the respirator.

Abstract: A method of fit testing includes providing a respirator; providing a sensor having a sensing element removably positioned substantially within an interior gas space of the respirator; providing a reader configured to be in wireless communication with the sensor; positioning the respirator over a mouth and a nose of a user while the sensor is positioned substantially within an interior gas space of the respirator; and observing respirator fit assessment data communicated from the sensor to the reader.

Abstract: There is provided a fit testing method comprising: providing a respirator donned by a wearer; providing a first sensor, where the sensor is configured to monitor a particulate concentration parameter within the respirator, where the first sensor is attached to the respirator such that the weight of the first sensor is supported by the respirator; providing a second sensor configured to monitor a particulate concentration parameter outside the respirator; and providing a reader configured to communicate with the sensor, where the reader is configured to provide a respirator fit parameter based on a comparison of the particulate concentration parameter within the respirator to the particulate concentration parameter outside the respirator.

Abstract: A voltage regulator for flyback-type high voltage supplies having a supplementary energy storage transformer with its secondary interconnected in series with the primary of the conventional flyback transformer, a control circuit for sensing (a) the generation of the conventional flyback pulse, (b) a reference voltage, and (c) a feedback voltage signal appearing at the output of the conventional flyback transformer and a switch for selectively applying energy to the primary of the supplemental energy storage transformer. The aforesaid switch being activated whenever the feedback voltage is less than the reference voltage and said switch being activated earlier in time as the aforesaid difference becomes greater.