Abstract: An illustrative example hydrogen concentration sensor includes a hydrogen chamber configured to isolate hydrogen within the hydrogen chamber from gas outside the hydrogen chamber. A hydrogen evolving electrode is configured to generate pure hydrogen within the hydrogen chamber. A reference electrode is situated to be exposed to pure hydrogen within the hydrogen chamber. A detection electrode associated with the reference electrode is situated to be exposed to gas outside the hydrogen chamber. The detection electrode is configured to provide an indication of a concentration of hydrogen in the gas outside the hydrogen chamber.

Abstract: A hydrogen concentration sensor may include a plurality of electrically conductive plates. A hydrogen evolving electrode assembly in a first location between two of the plates may be configured to generate hydrogen. A detection electrode assembly in a second location between two of the plates may be configured to provide an indication of a concentration of hydrogen in a fluid of interest. A plurality of isolating layers may include a first isolating layer at the first location between two of the plates and a second isolating layer at the second location between two of the plates. The first and second isolating layers may each include a sealant that secures the two plates together and seals a perimeter around the electrode assembly at the corresponding location. A method of assembling a hydrogen concentration sensor is also disclosed.

Abstract: An illustrative example hydrogen concentration sensor includes a plurality of electrically conductive plates. A hydrogen evolving electrode assembly in a first location between two of the plates is configured to generate hydrogen. A detection electrode assembly in a second location between two of the plates is configured to provide an indication of a concentration of hydrogen in a fluid of interest. A plurality of isolating layers includes a first isolating layer at the first location between two of the plates and a second isolating layer at the second location between two of the plates. The first and second isolating layers each include a sealant that secures the two plates together and seals a perimeter around the electrode assembly at the corresponding location.

Abstract: An illustrative example system for managing hydrogen utilization in a fuel cell power plant includes a first hydrogen concentration sensor that provides an indication of a first concentration of hydrogen in a fluid flowing into an anode inlet of the power plant. A second hydrogen concentration sensor provides an indication of a second concentration of hydrogen in a fluid flowing out of an anode exit of the power plant. A processor determines a utilization of hydrogen by the power plant based on the first and second concentrations.

Abstract: An illustrative example hydrogen concentration sensor includes a first end plate. A hydrogen evolving electrode assembly that generates hydrogen is situated adjacent the first end plate and at least partially exposed through an opening through the end plate. A separator plate is between the hydrogen evolving electrode assembly and a detection electrode assembly. The separator plate includes a passage to allow a flow of hydrogen generated by the hydrogen evolving electrode assembly to the detection electrode assembly. A second end plate is situated adjacent the detection electrode assembly and includes a second opening where a portion of the detection electrode assembly is exposed to a fluid of interest to provide an indication of a concentration of hydrogen in the fluid of interest.

Abstract: An illustrative example hydrogen concentration sensor includes a plurality of electrically conductive plates. A hydrogen evolving electrode assembly in a first location between two of the plates is configured to generate hydrogen. A detection electrode assembly in a second location between two of the plates is configured to provide an indication of a concentration of hydrogen in a fluid of interest. A plurality of isolating layers includes a first isolating layer at the first location between two of the plates and a second isolating layer at the second location between two of the plates. The first and second isolating layers each include a sealant that secures the two plates together and seals a perimeter around the electrode assembly at the corresponding location.

Abstract: An illustrative example hydrogen concentration sensor includes a first end plate. A hydrogen evolving electrode assembly that generates hydrogen is situated adjacent the first end plate and at least partially exposed through an opening through the end plate. A separator plate is between the hydrogen evolving electrode assembly and a detection electrode assembly. The separator plate includes a passage to allow a flow of hydrogen generated by the hydrogen evolving electrode assembly to the detection electrode assembly. A second end plate is situated adjacent the detection electrode assembly and includes a second opening where a portion of the detection electrode assembly is exposed to a fluid of interest to provide an indication of a concentration of hydrogen in the fluid of interest.

Abstract: An illustrative example system for managing hydrogen utilization in a fuel cell power plant includes a first hydrogen concentration sensor that provides an indication of a first concentration of hydrogen in a fluid flowing into an anode inlet of the power plant. A second hydrogen concentration sensor provides an indication of a second concentration of hydrogen in a fluid flowing out of an anode exit of the power plant. A processor determines a utilization of hydrogen by the power plant based on the first and second concentrations.

Abstract: An illustrative example hydrogen concentration sensor includes a hydrogen chamber configured to isolate hydrogen within the hydrogen chamber from gas outside the hydrogen chamber. A hydrogen evolving electrode is configured to generate pure hydrogen within the hydrogen chamber. A reference electrode is situated to be exposed to pure hydrogen within the hydrogen chamber. A detection electrode associated with the reference electrode is situated to be exposed to gas outside the hydrogen chamber. The detection electrode is configured to provide an indication of a concentration of hydrogen in the gas outside the hydrogen chamber.

Abstract: A headwear device includes an endothermic reactor and a trigger to initiate an endothermic reaction in a reactor while the headwear device is being worn on a wearer's head. The headwear device may preferably be utilized in, or conjunction with, a motorcycle safety helmet or similar crash protection device. The headwear device is intended to prevent or delay the onset of brain damage as a result of serious trauma or head injury.

Abstract: A headwear device includes an endothermic reactor and a trigger to initiate an endothermic reaction in a reactor while the headwear device is being worn on a wearer's head. The headwear device may preferably be utilized in, or conjunction with, a motorcycle safety helmet or similar crash protection device. The headwear device is intended to prevent or delay the onset of brain damage as a result of serious trauma or head injury.

Abstract: There is disclosed headwear comprising an endothermic reactor and a trigger to initiate an endothermic reaction in the reactor whilst being worn on a wearer's head. Such may preferentially be utilised in or in conjunction with a motorcycle safety helmet or similar crash protection device. The headwear is intended to prevent or delay the onset of brain damage as a result of serious trauma or head injury.