Abstract: A breathing apparatus designed to display at least one condition associated with the breathing apparatus to the user of the breathing apparatus. The breathing apparatus includes a breathing mask, a display assembly and a sensor assembly. The display assembly includes at least one display designed to display at least one condition of the display assembly and/or the sensor assembly. The breathing apparatus design can be designed to enable a third party to view at least one condition of the display assembly and/or the sensor assembly while a user is wearing the breathing mask. The breathing apparatus can include a sealing arrangement for forming a seal between a circuit board and/or other electronic components and a housing of the display assembly and/or the sensor assembly.

Abstract: Various types of wireless communication systems for masks or helmets can be mounted externally or internally on a mask. Different types of microphones can be employed, for example, a bone-conducting microphone or a directional microphone. Ear speakers mounted at various locations on the mask or helmet can be employed. Wireless communication is with a transceiver mounted in or on a lapel unit, a walkie-talkie, or at a remote location.

Abstract: A system and method of providing a wireless heads-up display for displaying the amount of breathing gas remaining in an associated breathing gas supply is provided. The system has a transmitter and a receiver. The transmitter has a pressure sensor and a controller for interpreting the sensed pressure into levels indicative of the amount of breathing gas remaining in the breathing gas supply. These levels are transmitted via radio frequency to the receiver. The receiver, which can be mounted in a breathing mask, includes a display for displaying the amount of breathing gas remaining in the associated breathing gas supply.

Abstract: Various types of wireless communication systems for masks or helmets can be mounted externally or internally on a mask. Different types of microphones can be employed, for example, a bone-conducting microphone or a directional microphone. Ear speakers mounted at various locations on the mask or helmet can be employed. Wireless communication is with a transceiver mounted in or on a lapel unit, a walkie-talkie, or at a remote location.

Abstract: A system and method of providing a wireless heads-up display for displaying the amount of breathing gas remaining in an associated breathing gas supply is provided. The system has a transmitter and a receiver. The transmitter has a pressure sensor and a controller for interpreting the sensed pressure into levels indicative of the amount of breathing gas remaining in the breathing gas supply. These levels are transmitted via radio frequency to the receiver. The receiver, which can be mounted in a breathing mask, includes a display for displaying the amount of breathing gas remaining in the associated breathing gas supply.

Abstract: A self-contained breathing apparatus (SCBA) based accountability system is provided. The system includes at least one communication module affixed to the SCBA. The communication module includes, for example, an electronic key port configured to accept an electronic key device having identification information, at least one sensor port for interfacing with at least one sensor system, and a controller in circuit communication with said electronic key port. The communication module reads, stores, and transmits the identification information to a command post for remote monitoring. The communication module also transmits data received through the sensor port to the command post. The sensor system that interfaces with the communication module can include a wide variety of sensors including, for example, a pressure sensor for sensing pressure from the breathing gas tank of the SCBA. Other Insensors include temperature, gas, and physiological sensors.

Abstract: A frequency synthesizer or a circuit for deleting cycles from a wave source includes a dual modulus counter responsive to a reference frequency source of the synthesizer or waves of the source. The dual modulus counter selectively decreases the number of cycles of the source by the factors K.sub.2 and (K.sub.2 +1). A frequency divider divides the frequency of the source by a third factor L to derive an output wave. The dual modulus counter is activated so it divides by K.sub.2 +1, whereby the dual modulus counter derives an output signal having a frequency F.sub.0 =F.sub.in /K.sub.2 (1-1/L), where F.sub.in equals the frequency of the source, L is an integer and K.sub.2 is an integer greater than L.