Exposure indicating apparatus

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to an air purifying cartridge located along the flow-through path such that the processor housing is detachable without allowing ambient air to enter the flow-through path, the air purifying cartridge including receiving means for releasable engagement with the processor housing wherein the receiving means comprises a plurality of generally parallel walls restricting engagement and disengagement of the processor housing with the receiving means along a single axis;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to an air purifying cartridge located along the flow-through path such that the processor housing is detachable without allowing ambient air to enter the flow-through path, and wherein the reversible sensor is located in the processor housing and the processor housing further includes a fluidic coupling in fluid communication with the air purifying cartridge:
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to an air purifying cartridge located along the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location, the reversible sensor is located in the processor housing, the processor housing further including a fluidic coupling in fluid communication with the air purifying cartridge, wherein the fluidic coupling comprises a diffusion limiting device:
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a flow-through housing forming a portion of the flow-through path interposed between an air purifying cartridge and the face mask;
• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through housing at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a flow-through housing forming a portion of the flow-through path;
• a processor housing releasably attached to the flow-through housing at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a reversible sensor located within the processor housing, the processor housing further including a fluidic coupling in fluid communication with the flow-through path;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a flow-through housing forming a portion of the flow-through path;
• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through housing at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location, wherein the flow-through housing includes receiving means comprising a plurality of generally parallel walls restricting engagement and disengagement of the processor housing with the receiving means along a single axis;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• a indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the face mask at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask and further extending from the face mask to the external environment through an exhaust port, comprising:

• a reversible sensor located in the mask in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal, wherein the processing device operates the indicator at a signaling rate which varies as a continuous function of the concentration signal.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• and
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor, wherein the processing device is responsive to a concentration signal from the reversible sensor, the processing device operating a single signal indicator at an exposure signaling rate which varies as a function of the concentration signal, a ready signaling rate indicative of a correctly functioning alarm, and a fault signaling rate indicative of an exposure indicator functioning outside of predetermined operating parameters.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending from at least an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• processor housing means for releasable attachment to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• processing means contained in the processor housing for generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• signaling means responsive to the concentration signal for signaling the user.

A face mask with an exposure indicating apparatus comprising:

• a face mask defining a face mask chamber extending across at least the mouth and nose of a user, the face mask having a flow-through path extending from at least an external environment through the face mask chamber;
• an air purifying respirator cartridge located along the flow-through path in fluidic engagement with the face mask chamber;
• a reversible sensor in fluid communication with the flow-through path for monitoring the air flowing along a flow-through path;
• a processor housing releasably attached to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration.

An air purifying respirator cartridge for use with an exposure indicating apparatus, the exposure indicating apparatus including a sensor, comprising:

• filter media;
• a cartridge housing containing the filter media defining at least a portion of a flow-through path between an external environment and a face mask;
• receiving means on the cartridge housing for releasable engagement with the exposure indicating apparatus;
• and
• transmission means for permitting the sensor to monitor the filter media without permitting ambient air to enter the flow-through path at the receiving means upon disengagement of the exposure indicating apparatus from the cartridge housing.

An air purifying respirator cartridge for use with an exposure indicating apparatus containing a sensor, comprising:

• filter media;
• a cartridge housing containing the filter media defining at least a portion of a flow-through path between an external environment and a face mask;
• receiving means on the cartridge housing for releasable engagement with an exposure indicating apparatus, wherein the sensor is located proximate the receiving means;
• and
• transmission means for permitting the sensor to monitor the filter media without permitting ambient air to enter the flow-through path at the receiving means upon disengagement of the exposure indicating apparatus from the cartridge housing and wherein the transmission means comprises a diffusion limiting device.

A flow-through housing interposed between an air purifying cartridge and a face mask for use with an exposure indicating apparatus including a sensor, comprising:

• a housing forming a portion of a flow-through path between an external environment and the face mask;
• receiving means on the housing for releasable engagement with the exposure indicating apparatus including the sensor;
• and
• transmission means for permitting the sensor to monitor the flow-through path, the receiving means permitting the exposure indicating apparatus to be removed from the housing without permitting ambient air to enter the flow-through path at the receiving means.

A method for monitoring the presence of target species in air flowing from an external environment through a face mask along a flow-through path, comprising the steps of:

• providing a reversible sensor in fluid communication with the flow-through path and a processor housing containing a processing device releasably attached to the flow-through path at an attachment location so that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location;
• monitoring at least one property of the reversible sensor;
• generating a concentration signal in response to the at least one property of the reversible sensor;
• and
• activating an indicator in response to the concentration signal.

A method for attaching an exposure indicator located along a flow-through path extending from an external environment through a face mask, comprising the steps of:

• interposing a flow-through housing forming a portion of the flow through path between an air purifying cartridge and the face mask,
• providing at least one reversible sensor in fluid communication with the flow-through housing;
• and
• releasably attaching a processor housing to the flow-through housing at an attachment location so that the processor housing is detachable from the flow-through housing without allowing ambient air to enter the flow-through path at the attachment location, the processor housing containing an indicator responsive to at least one property of the reversible sensor.

An exposure indicating apparatus for monitoring the presence of a target species in air flowing along a flow-through path extending at least from an external environment through a face mask, comprising:

• a reversible sensor in fluid communication with the flow-through path;
• a processor housing releasably attached to the flow-through path at an attachment location such that the processor housing is detachable without allowing ambient air to enter the flow-through path at the attachment location, the reversible sensor is located in the processor housing, the processor housing further including a fluidic coupling in fluid communication with the flow-through path, a diffusion limiting device interposed between the reversible sensor and the flow-through path;
• a processing device contained in the processor housing generating a concentration signal responsive to at least one property of the reversible sensor;
• and
• an indicator responsive to the concentration signal.